diff --git a/.github/workflows/deploy-pypi.yml b/.github/workflows/deploy-pypi.yml
index 509543c..258a9de 100644
--- a/.github/workflows/deploy-pypi.yml
+++ b/.github/workflows/deploy-pypi.yml
@@ -122,7 +122,11 @@ jobs:
         run: |
           sudo apt update
           sudo apt install -y libxcb-cursor0 qt6-base-dev patchelf ccache zlib1g-dev
+          sudo apt install -y flatpak flatpak-builder elfutils patchelf
           echo "QMAKE=$(which qmake6)" >> $GITHUB_ENV
+          flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
+          flatpak update
+          flatpak install flathub org.kde.Platform//6.8 org.kde.Sdk//6.8
 
           if [ "$RUNNER_ARCH" == "X64" ]; then
             linuxdeploy_arch="x86_64"
@@ -219,6 +223,8 @@ jobs:
             Furious-*.zip
             Furious-*.dmg
             Furious-*.AppImage
+            Furious-*.deb
+            Furious-*.flatpak
 
   github-release:
     name: Upload to GitHub Release
diff --git a/.gitignore b/.gitignore
index 6df27f7..6b65e63 100644
--- a/.gitignore
+++ b/.gitignore
@@ -170,6 +170,10 @@ Furious-*/
 
 # Linux app dir
 AppDir/
+# Linux debian dir
+debian/
+# Linux flatpak dir
+flatpak/
 
 # zip files
 *.zip
@@ -177,3 +181,7 @@ AppDir/
 *.dmg
 # AppImage files
 *.AppImage
+# deb files
+*.deb
+# flatpak files
+*.flatpak
diff --git a/Deploy.py b/Deploy.py
index b93853a..8da35d6 100644
--- a/Deploy.py
+++ b/Deploy.py
@@ -54,6 +54,8 @@ NUITKA_BINARY_VERSION_OPTION = (
     f'--product-version={APPLICATION_VERSION} '
 )
 
+PLATFORM_MACHINE_LOWER = PLATFORM_MACHINE.lower()
+
 if PLATFORM == 'Windows':
     NUITKA_BINARY_VERSION_OPTION += f'--file-description=\"A GUI proxy client based on PySide6. Support Xray-core & hysteria\" '
 
@@ -118,7 +120,7 @@ if PLATFORM == 'Windows':
 
     ARTIFACT_NAME = (
         f'{APPLICATION_NAME}-{APPLICATION_VERSION}-'
-        f'{winVerCompatible}-{PLATFORM_MACHINE.lower()}'
+        f'{winVerCompatible}-{PLATFORM_MACHINE_LOWER}'
     )
 
     WIN_UNZIPPED = f'{APPLICATION_NAME}-{APPLICATION_VERSION}-{winVerCompatible}'
@@ -135,7 +137,7 @@ elif PLATFORM == 'Darwin':
 
     ARTIFACT_NAME = (
         f'{APPLICATION_NAME}-{APPLICATION_VERSION}-'
-        f'{macVerCompatible}-{PLATFORM_MACHINE.lower()}'
+        f'{macVerCompatible}-{PLATFORM_MACHINE_LOWER}'
     )
 
     MAC_APP_DIR = ROOT_DIR / 'app'
@@ -159,7 +161,7 @@ elif PLATFORM == 'Linux':
     LINUX_DESKTOP_FILE = f'{APPLICATION_NAME}.desktop'
 
     ARTIFACT_NAME = (
-        f'{APPLICATION_NAME}-{APPLICATION_VERSION}-linux-{PLATFORM_MACHINE.lower()}'
+        f'{APPLICATION_NAME}-{APPLICATION_VERSION}-linux-{PLATFORM_MACHINE_LOWER}'
     )
 
     LINUX_APPIMAGE_FILENAME = f'{ARTIFACT_NAME}.AppImage'
@@ -171,6 +173,12 @@ elif PLATFORM == 'Linux':
         f'--plugin qt '
         f'--output appimage'
     )
+
+    LINUX_DEBIAN_DIR = ROOT_DIR / 'debian'
+    LINUX_DEB_FILENAME = f'{ARTIFACT_NAME}.deb'
+
+    LINUX_FLATPAK_DIR = ROOT_DIR / 'flatpak'
+    LINUX_FLATPAK_FILENAME = f'{ARTIFACT_NAME}.flatpak'
 else:
     # Deploy: Not implemented
     ARTIFACT_NAME = ''
@@ -330,6 +338,7 @@ def cleanup():
             logger.info(f'remove app dir success')
     elif PLATFORM == 'Linux':
         # More cleanup on Linux
+        # Cleanup AppImage environment
         try:
             # Remove artifact
             os.remove(ROOT_DIR / LINUX_APPIMAGE_FILENAME)
@@ -349,6 +358,48 @@ def cleanup():
             logger.error(f'remove app dir failed: {ex}')
         else:
             logger.info(f'remove app dir success')
+
+        # Cleanup deb environment
+        try:
+            # Remove artifact
+            os.remove(ROOT_DIR / LINUX_DEB_FILENAME)
+        except Exception as ex:
+            # Any non-exit exceptions
+
+            logger.error(f'remove artifact failed: {ex}')
+        else:
+            logger.info(f'remove artifact success')
+
+        try:
+            # Remove debian folder
+            shutil.rmtree(LINUX_DEBIAN_DIR)
+        except Exception as ex:
+            # Any non-exit exceptions
+
+            logger.error(f'remove debian dir failed: {ex}')
+        else:
+            logger.info(f'remove debian dir success')
+
+        # Cleanup flatpak environment
+        try:
+            # Remove artifact
+            os.remove(ROOT_DIR / LINUX_FLATPAK_FILENAME)
+        except Exception as ex:
+            # Any non-exit exceptions
+
+            logger.error(f'remove artifact failed: {ex}')
+        else:
+            logger.info(f'remove artifact success')
+
+        try:
+            # Remove flatpak folder
+            shutil.rmtree(LINUX_FLATPAK_DIR)
+        except Exception as ex:
+            # Any non-exit exceptions
+
+            logger.error(f'remove flatpak dir failed: {ex}')
+        else:
+            logger.info(f'remove flatpak dir success')
     else:
         # Deploy: Not implemented
         pass
@@ -527,20 +578,23 @@ def main():
             LINUX_APP_DIR,
         )
 
+        DESKTOP_FILE_CONTENT = (
+            f'[Desktop Entry]\n'
+            f'Type=Application\n'
+            f'Name={APPLICATION_NAME}\n'
+            f'Exec={APPLICATION_NAME}.bin\n'
+            f'Icon={iconbase}\n'
+            f'Terminal=false\n'
+            f'Categories=Utility\n'
+        )
+
         try:
             with open(
                 LINUX_APP_DIR / LINUX_DESKTOP_FILE,
                 'w',
                 encoding='utf-8',
             ) as file:
-                file.write(
-                    f'[Desktop Entry]\n'
-                    f'Type=Application\n'
-                    f'Name={APPLICATION_NAME}\n'
-                    f'Exec={APPLICATION_NAME}.bin\n'
-                    f'Icon={iconbase}\n'
-                    f'Categories=Utility\n'
-                )
+                file.write(DESKTOP_FILE_CONTENT)
         except Exception:
             # Any non-exit exceptions
 
@@ -589,6 +643,322 @@ def main():
             logger.info(f'chmod +x success: {LINUX_APPIMAGE_FILENAME}')
 
             printStandardStream(result.stdout, result.stderr)
+
+        # Create .deb package
+        logger.info('generating deb')
+
+        # Prepare package layout
+        try:
+            os.makedirs(LINUX_DEBIAN_DIR / 'DEBIAN', exist_ok=True)
+            os.makedirs(LINUX_DEBIAN_DIR / 'usr' / 'bin', exist_ok=True)
+            os.makedirs(
+                LINUX_DEBIAN_DIR / 'usr' / 'share' / APPLICATION_NAME,
+                exist_ok=True,
+            )
+            os.makedirs(
+                LINUX_DEBIAN_DIR / 'usr' / 'share' / 'applications',
+                exist_ok=True,
+            )
+            os.makedirs(
+                LINUX_DEBIAN_DIR
+                / 'usr'
+                / 'share'
+                / 'icons'
+                / 'hicolor'
+                / '512x512'
+                / 'apps',
+                exist_ok=True,
+            )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Copy output
+        shutil.copytree(
+            ROOT_DIR / DEPLOY_DIR_NAME / f'{APPLICATION_NAME}.dist',
+            LINUX_DEBIAN_DIR / 'usr' / 'share' / APPLICATION_NAME,
+            dirs_exist_ok=True,
+        )
+        shutil.copy(
+            ROOT_DIR / 'Icons' / 'png' / f'{iconbase}.png',
+            LINUX_DEBIAN_DIR
+            / 'usr'
+            / 'share'
+            / 'icons'
+            / 'hicolor'
+            / '512x512'
+            / 'apps',
+        )
+
+        # Create launcher script
+        try:
+            launcherScript = LINUX_DEBIAN_DIR / 'usr' / 'bin' / APPLICATION_NAME
+
+            with open(
+                launcherScript,
+                'w',
+                encoding='utf-8',
+            ) as file:
+                file.write(
+                    f'#!/bin/bash\n'
+                    f'exec /usr/share/{APPLICATION_NAME}/{APPLICATION_NAME}.bin "$@"\n'
+                )
+
+            runExternalCommand(
+                f'chmod +x {launcherScript}',
+                shell=True,
+                check=True,
+            )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Create desktop entry file
+        try:
+            with open(
+                LINUX_DEBIAN_DIR
+                / 'usr'
+                / 'share'
+                / 'applications'
+                / LINUX_DESKTOP_FILE,
+                'w',
+                encoding='utf-8',
+            ) as file:
+                file.write(DESKTOP_FILE_CONTENT)
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Create control file
+        try:
+            if PLATFORM_MACHINE_LOWER == 'x86_64':
+                arch = 'amd64'
+            elif PLATFORM_MACHINE_LOWER == 'aarch64':
+                arch = 'arm64'
+            else:
+                raise
+
+            with open(
+                LINUX_DEBIAN_DIR / 'DEBIAN' / 'control',
+                'w',
+                encoding='utf-8',
+            ) as file:
+                file.write(
+                    f'Package: {APPLICATION_NAME}\n'
+                    f'Version: {APPLICATION_VERSION}\n'
+                    f'Section: utils\n'
+                    f'Priority: optional\n'
+                    f'Architecture: {arch}\n'
+                    f'Depends: libc6, libstdc++6, libgl1, libxcb-cursor0, libxcb-xinerama0\n'
+                    f'Maintainer: {APPLICATION_AUTHOR_NAME} <{APPLICATION_AUTHOR_EMAIL}>\n'
+                    f'Description: A GUI proxy client based on PySide6. Support Xray-core & hysteria\n'
+                    f'Homepage: {APPLICATION_ABOUT_PAGE}\n'
+                )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Fix permissions
+        try:
+            runExternalCommand(
+                f'find debian -type d -exec chmod 755 {{}} \\;',
+                shell=True,
+                check=True,
+            )
+            runExternalCommand(
+                f'find debian -type f -exec chmod 644 {{}} \\;',
+                shell=True,
+                check=True,
+            )
+            runExternalCommand(
+                f'chmod 755 '
+                + (LINUX_DEBIAN_DIR / 'usr' / 'bin' / APPLICATION_NAME).as_posix(),
+                shell=True,
+                check=True,
+            )
+            runExternalCommand(
+                f'chmod 755 '
+                + (
+                    LINUX_DEBIAN_DIR
+                    / 'usr'
+                    / 'share'
+                    / APPLICATION_NAME
+                    / f'{APPLICATION_NAME}.bin'
+                ).as_posix(),
+                shell=True,
+                check=True,
+            )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        try:
+            runExternalCommand(
+                f'dpkg-deb --build debian {LINUX_DEB_FILENAME}',
+                shell=True,
+                check=True,
+            )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Create .flatpak package
+        logger.info('generating flatpak')
+
+        # Prepare package layout
+        try:
+            os.makedirs(LINUX_FLATPAK_DIR / APPLICATION_NAME, exist_ok=True)
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Copy output
+        shutil.copytree(
+            ROOT_DIR / DEPLOY_DIR_NAME / f'{APPLICATION_NAME}.dist',
+            LINUX_FLATPAK_DIR / APPLICATION_NAME,
+            dirs_exist_ok=True,
+        )
+        shutil.copy(
+            ROOT_DIR / 'Icons' / 'png' / f'{iconbase}.png',
+            LINUX_FLATPAK_DIR / f'{APPLICATION_FLATPAK_ID}.png',
+        )
+
+        # Create flatpak manifest file
+        try:
+            with open(
+                LINUX_FLATPAK_DIR / f'{APPLICATION_FLATPAK_ID}.yml',
+                'w',
+                encoding='utf-8',
+            ) as file:
+                file.write(
+                    f'app-id: {APPLICATION_FLATPAK_ID}\n'
+                    f'runtime: org.kde.Platform\n'
+                    f'runtime-version: \"6.8\"\n'
+                    f'sdk: org.kde.Sdk\n'
+                    f'command: {APPLICATION_NAME}\n'
+                    f'\n'
+                    f'finish-args:\n'
+                    f'  - --share=ipc\n'
+                    f'  - --share=network\n'
+                    f'  - --socket=wayland\n'
+                    f'  - --socket=fallback-x11\n'
+                    f'  - --device=dri\n'
+                    f'  - --filesystem=home\n'
+                    f'  - --talk-name=org.freedesktop.Flatpak\n'
+                    f'\n'
+                    f'modules:\n'
+                    f'  - name: mit-krb5\n'
+                    f'    buildsystem: simple\n'
+                    f'    sources:\n'
+                    f'      - type: archive\n'
+                    f'        url: https://kerberos.org/dist/krb5/1.21/krb5-1.21.3.tar.gz\n'
+                    f'        sha256: b7a4cd5ead67fb08b980b21abd150ff7217e85ea320c9ed0c6dadd304840ad35\n'
+                    f'    build-commands:\n'
+                    f'      - cd src && autoreconf -i  # Ensure Autotools files are generated\n'
+                    f'      - cd src && ./configure --prefix=/app --disable-static --enable-shared\n'
+                    f'      - cd src && make -j$(nproc)\n'
+                    f'      - cd src && make install\n'
+                    f'  - name: {APPLICATION_NAME}\n'
+                    f'    buildsystem: simple\n'
+                    f'    build-commands:\n'
+                    f'      # Script\n'
+                    f'      - install -Dm755 {APPLICATION_NAME}.sh /app/bin/{APPLICATION_NAME}\n'
+                    f'      # Whole application directory\n'
+                    f'      - mkdir -p /app/lib/{APPLICATION_NAME}/\n'
+                    f'      - cp -a . /app/lib/{APPLICATION_NAME}/\n'
+                    f'      # Desktop + icon\n'
+                    f'      - install -Dm644 {APPLICATION_FLATPAK_ID}.desktop /app/share/applications/{APPLICATION_FLATPAK_ID}.desktop\n'
+                    f'      - install -Dm644 {APPLICATION_FLATPAK_ID}.png /app/share/icons/hicolor/512x512/apps/{APPLICATION_FLATPAK_ID}.png\n'
+                    f'    sources:\n'
+                    f'      - type: file\n'
+                    f'        path: {APPLICATION_NAME}.sh\n'
+                    f'      - type: dir\n'
+                    f'        path: {APPLICATION_NAME}\n'
+                    f'      - type: file\n'
+                    f'        path: {APPLICATION_FLATPAK_ID}.desktop\n'
+                    f'      - type: file\n'
+                    f'        path: {APPLICATION_FLATPAK_ID}.png\n'
+                )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Create desktop entry file
+        try:
+            with open(
+                LINUX_FLATPAK_DIR / f'{APPLICATION_FLATPAK_ID}.desktop',
+                'w',
+                encoding='utf-8',
+            ) as file:
+                file.write(
+                    f'[Desktop Entry]\n'
+                    f'Type=Application\n'
+                    f'Name={APPLICATION_NAME}\n'
+                    f'Exec={APPLICATION_NAME}\n'
+                    f'Icon={APPLICATION_FLATPAK_ID}\n'
+                    f'Terminal=false\n'
+                    f'Categories=Utility\n'
+                )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        # Create launcher script
+        try:
+            with open(
+                LINUX_FLATPAK_DIR / f'{APPLICATION_NAME}.sh',
+                'w',
+                encoding='utf-8',
+            ) as file:
+                file.write(
+                    f'#!/usr/bin/env bash\n'
+                    f'exec /app/lib/{APPLICATION_NAME}/{APPLICATION_NAME}.bin \"$@\"\n'
+                )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+
+        cwd = os.getcwd()
+
+        try:
+            os.chdir(LINUX_FLATPAK_DIR)
+
+            runExternalCommand(
+                f'flatpak-builder build-dir {APPLICATION_FLATPAK_ID}.yml --force-clean',
+                shell=True,
+                check=True,
+            )
+            runExternalCommand(
+                f'flatpak build-export repo build-dir',
+                shell=True,
+                check=True,
+            )
+            runExternalCommand(
+                f'flatpak build-bundle repo {LINUX_FLATPAK_FILENAME} {APPLICATION_FLATPAK_ID}',
+                shell=True,
+                check=True,
+            )
+
+            shutil.copy(
+                LINUX_FLATPAK_FILENAME,
+                ROOT_DIR,
+            )
+        except Exception:
+            # Any non-exit exceptions
+
+            raise
+        finally:
+            os.chdir(cwd)
     else:
         # Deploy: Not implemented
         pass
diff --git a/Furious/Core/CoreManager.py b/Furious/Core/CoreManager.py
index 017905c..1d8026d 100644
--- a/Furious/Core/CoreManager.py
+++ b/Furious/Core/CoreManager.py
@@ -21,7 +21,6 @@ from Furious.Frozenlib import *
 from Furious.Interface import *
 from Furious.Library import *
 from Furious.Qt import *
-from Furious.Utility import *
 from Furious.Core.CoreProcessWorker import *
 from Furious.Core.XrayCore import *
 from Furious.Core.Hysteria1 import *
@@ -30,6 +29,7 @@ from Furious.Core.Tun2socks import *
 
 from typing import Callable, Tuple, Union
 
+import os
 import uuid
 import logging
 import tempfile
@@ -654,8 +654,13 @@ class CoreManager(Mixins.CleanupOnExit):
                     )
                 )
 
+                if SystemRuntime.flatpakID():
+                    tempdir = os.environ.get('TMPDIR')
+                else:
+                    tempdir = None
+
                 with tempfile.NamedTemporaryFile(
-                    mode='w', encoding='utf-8', suffix='.sh', delete=True
+                    mode='w', encoding='utf-8', suffix='.sh', dir=tempdir, delete=True
                 ) as file:
                     content = '\n'.join(
                         filter(
diff --git a/Furious/Core/CoreProcessWorker.py b/Furious/Core/CoreProcessWorker.py
index 1bb288e..c4c2246 100644
--- a/Furious/Core/CoreProcessWorker.py
+++ b/Furious/Core/CoreProcessWorker.py
@@ -19,7 +19,6 @@ from __future__ import annotations
 
 from Furious.Frozenlib import *
 from Furious.Interface import *
-from Furious.Utility import *
 
 from PySide6 import QtCore
 
diff --git a/Furious/Core/XrayCore.py b/Furious/Core/XrayCore.py
index aa5f70a..0ff6b0e 100644
--- a/Furious/Core/XrayCore.py
+++ b/Furious/Core/XrayCore.py
@@ -20,7 +20,6 @@ from __future__ import annotations
 from Furious.Frozenlib import *
 from Furious.Interface import *
 from Furious.Library import *
-from Furious.Utility import *
 from Furious.Core.CoreProcessWorker import *
 
 from enum import Enum
diff --git a/Furious/Frozenlib/Constants.py b/Furious/Frozenlib/Constants.py
index 00e5f45..2c8c63f 100644
--- a/Furious/Frozenlib/Constants.py
+++ b/Furious/Frozenlib/Constants.py
@@ -26,8 +26,11 @@ import platform
 
 APPLICATION_NAME = 'Furious'
 APPLICATION_VERSION = __version__
+APPLICATION_AUTHOR_NAME = 'Loren Eteval'
+APPLICATION_AUTHOR_EMAIL = 'loren.eteval@proton.me'
 APPLICATION_MACOS_SIGNATURE = 'com.Furious'
-APPLICATION_REPO_OWNER_NAME = 'LorenEteval'
+APPLICATION_FLATPAK_ID = 'com.Furious.Furious'
+APPLICATION_REPO_OWNER_NAME = APPLICATION_AUTHOR_NAME.replace(' ', '')
 APPLICATION_REPO_NAME = 'Furious'
 APPLICATION_ABOUT_PAGE = (
     f'https://github.com/{APPLICATION_REPO_OWNER_NAME}/{APPLICATION_REPO_NAME}'
diff --git a/Furious/Utility/StartupOnBoot.py b/Furious/Frozenlib/StartupOnBoot.py
similarity index 98%
rename from Furious/Utility/StartupOnBoot.py
rename to Furious/Frozenlib/StartupOnBoot.py
index 7046d51..8fe9e8d 100644
--- a/Furious/Utility/StartupOnBoot.py
+++ b/Furious/Frozenlib/StartupOnBoot.py
@@ -15,8 +15,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-from Furious.Frozenlib import *
-from Furious.Utility.SystemRuntime import *
+from Furious.Frozenlib.Constants import *
+from Furious.Frozenlib.SystemRuntime import *
 
 from PySide6 import QtCore
 
diff --git a/Furious/Utility/SystemProxy.py b/Furious/Frozenlib/SystemProxy.py
similarity index 96%
rename from Furious/Utility/SystemProxy.py
rename to Furious/Frozenlib/SystemProxy.py
index 332a177..2046719 100644
--- a/Furious/Utility/SystemProxy.py
+++ b/Furious/Frozenlib/SystemProxy.py
@@ -17,7 +17,11 @@
 
 from __future__ import annotations
 
-from Furious.Frozenlib import *
+from Furious.Frozenlib.Constants import *
+from Furious.Frozenlib.Enum import *
+from Furious.Frozenlib.AppSettings import *
+from Furious.Frozenlib.Utility import *
+from Furious.Frozenlib.SystemRuntime import *
 
 import logging
 import subprocess
@@ -43,9 +47,14 @@ def handleAppSystemProxyMode() -> bool:
 
 
 def linuxProxyConfig(proxy_args, arg0, arg1):
+    command = 'gsettings'
+
+    if SystemRuntime.flatpakID():
+        command = 'flatpak-spawn --host ' + command
+
     runExternalCommand(
-        [
-            'gsettings',
+        command.split()
+        + [
             'set',
             'org.gnome.system.' + proxy_args,
             arg0,
diff --git a/Furious/Frozenlib/SystemRoutingTable.py b/Furious/Frozenlib/SystemRoutingTable.py
index b99d055..90109c2 100644
--- a/Furious/Frozenlib/SystemRoutingTable.py
+++ b/Furious/Frozenlib/SystemRoutingTable.py
@@ -19,6 +19,7 @@ from __future__ import annotations
 
 from Furious.Frozenlib.Constants import *
 from Furious.Frozenlib.Utility import *
+from Furious.Frozenlib.SystemRuntime import *
 
 import re
 import logging
@@ -335,9 +336,14 @@ class SystemRoutingTable:
     def LinuxFindTUNDevice(deviceName: str) -> bool:
         assert PLATFORM == 'Linux'
 
+        command = 'ip tuntap show'
+
+        if SystemRuntime.flatpakID():
+            command = 'flatpak-spawn --host ' + command
+
         try:
             result = runExternalCommand(
-                'ip tuntap show'.split(),
+                command.split(),
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 check=True,
@@ -364,9 +370,14 @@ class SystemRoutingTable:
     def LinuxDeleteTUNDevice(deviceName: str) -> bool:
         assert PLATFORM == 'Linux'
 
+        command = 'ip tuntap del mode tun dev'
+
+        if SystemRuntime.flatpakID():
+            command = 'flatpak-spawn --host ' + command
+
         try:
             result = runExternalCommand(
-                'ip tuntap del mode tun dev'.split() + [deviceName],
+                command.split() + [deviceName],
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 check=True,
@@ -396,9 +407,14 @@ class SystemRoutingTable:
     def LinuxExecutePrivilegedScript(filepath, shell='bash') -> bool:
         assert PLATFORM == 'Linux'
 
+        command = 'pkexec'
+
+        if SystemRuntime.flatpakID():
+            command = 'flatpak-spawn --host ' + command
+
         try:
             result = runExternalCommand(
-                ['pkexec', shell, filepath],
+                command.split() + [shell, filepath],
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 check=True,
@@ -428,9 +444,14 @@ class SystemRoutingTable:
     def LinuxGetIpRoute() -> str:
         assert PLATFORM == 'Linux'
 
+        command = 'ip route show'
+
+        if SystemRuntime.flatpakID():
+            command = 'flatpak-spawn --host ' + command
+
         try:
             result = runExternalCommand(
-                'ip route show'.split(),
+                command.split(),
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 check=True,
@@ -483,8 +504,13 @@ class SystemRoutingTable:
                 )
 
             if PLATFORM == 'Linux':
+                command = 'ip route show default'
+
+                if SystemRuntime.flatpakID():
+                    command = 'flatpak-spawn --host ' + command
+
                 result = runExternalCommand(
-                    'ip route show default'.split(),
+                    command.split(),
                     stdout=subprocess.PIPE,
                     stderr=subprocess.PIPE,
                     check=True,
diff --git a/Furious/Utility/SystemRuntime.py b/Furious/Frozenlib/SystemRuntime.py
similarity index 90%
rename from Furious/Utility/SystemRuntime.py
rename to Furious/Frozenlib/SystemRuntime.py
index 4e391aa..1d92a08 100644
--- a/Furious/Utility/SystemRuntime.py
+++ b/Furious/Frozenlib/SystemRuntime.py
@@ -17,7 +17,9 @@
 
 from __future__ import annotations
 
-from Furious.Frozenlib import *
+from Furious.Frozenlib.Constants import *
+from Furious.Frozenlib.Utility import *
+from Furious.Frozenlib.AppSettings import *
 
 import os
 import sys
@@ -70,6 +72,16 @@ class SystemRuntime:
         else:
             return ''
 
+    @staticmethod
+    def flatpakID() -> str:
+        if PLATFORM != 'Linux':
+            return ''
+
+        if 'FLATPAK_ID' in os.environ:
+            return os.environ['FLATPAK_ID']
+        else:
+            return ''
+
     @staticmethod
     @functools.lru_cache(None)
     def isAdmin() -> bool:
diff --git a/Furious/Frozenlib/__init__.py b/Furious/Frozenlib/__init__.py
index e9f2dfc..31573e3 100644
--- a/Furious/Frozenlib/__init__.py
+++ b/Furious/Frozenlib/__init__.py
@@ -21,7 +21,10 @@ from .Enum import *
 from .Globals import *
 from .Mixins import *
 from .PySide6Legacy import *
+from .StartupOnBoot import *
+from .SystemProxy import *
 from .SystemRoutingTable import *
+from .SystemRuntime import *
 from .Tcping import *
 from .Utility import *
 from .Win32Session import *
diff --git a/Furious/Qt/DynamicTheme.py b/Furious/Qt/DynamicTheme.py
index 1fd5541..28f19ed 100644
--- a/Furious/Qt/DynamicTheme.py
+++ b/Furious/Qt/DynamicTheme.py
@@ -19,7 +19,6 @@ from __future__ import annotations
 
 from Furious.Frozenlib import *
 from Furious.Qt.QtGui import *
-from Furious.Utility import *
 
 __all__ = ['AppHue']
 
diff --git a/Furious/Qt/QtGui.py b/Furious/Qt/QtGui.py
index 50c68a1..e78c5d3 100644
--- a/Furious/Qt/QtGui.py
+++ b/Furious/Qt/QtGui.py
@@ -17,7 +17,6 @@
 
 from Furious.Frozenlib import *
 from Furious.Qt.DynamicTranslate import gettext as _
-from Furious.Utility import *
 
 from PySide6 import QtCore
 from PySide6.QtGui import *
diff --git a/Furious/TrayActions/Connect.py b/Furious/TrayActions/Connect.py
index 128f2dc..1ef08e1 100644
--- a/Furious/TrayActions/Connect.py
+++ b/Furious/TrayActions/Connect.py
@@ -22,7 +22,6 @@ from Furious.Interface import *
 from Furious.Library import *
 from Furious.Qt import *
 from Furious.Qt import gettext as _
-from Furious.Utility import *
 from Furious.Core import *
 from Furious.Widget.ConnectProgressBar import ConnectProgressBar
 
diff --git a/Furious/TrayActions/Settings.py b/Furious/TrayActions/Settings.py
index d51fde2..6c27d49 100644
--- a/Furious/TrayActions/Settings.py
+++ b/Furious/TrayActions/Settings.py
@@ -20,7 +20,6 @@ from __future__ import annotations
 from Furious.Frozenlib import *
 from Furious.Qt import *
 from Furious.Qt import gettext as _
-from Furious.Utility import *
 
 __all__ = ['SettingsAction']
 
diff --git a/Furious/Utility/__init__.py b/Furious/Utility/__init__.py
index 4b07a40..7af5999 100644
--- a/Furious/Utility/__init__.py
+++ b/Furious/Utility/__init__.py
@@ -15,7 +15,4 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-from .StartupOnBoot import *
-from .SystemProxy import *
-from .SystemRuntime import *
 from .AppMainProcess import *
diff --git a/Furious/Widget/Application.py b/Furious/Widget/Application.py
index 98276d7..c5ef140 100644
--- a/Furious/Widget/Application.py
+++ b/Furious/Widget/Application.py
@@ -19,7 +19,6 @@ from Furious.Frozenlib import *
 from Furious.Interface import *
 from Furious.Qt import gettext as _
 from Furious.Library import *
-from Furious.Utility import *
 from Furious.Widget.SystemTrayIcon import *
 from Furious.Window.AppMainWindow import *
 from Furious.Window.LogViewerWindow import *
@@ -261,6 +260,12 @@ class Application(ApplicationFactory, SingletonApplication):
         # Xray environment variables
         os.environ['XRAY_LOCATION_ASSET'] = str(XRAY_ASSET_DIR)
 
+        if SystemRuntime.flatpakID():
+            # https://github.com/flatpak/flatpak/issues/3438
+            os.environ['TMPDIR'] = os.path.join(
+                os.environ.get('XDG_RUNTIME_DIR'), 'app', APPLICATION_FLATPAK_ID
+            )
+
     def addStorage(self):
         # Protected storage access
         self._userActivatedItemIndex = Storage.UserActivatedItemIndex()
@@ -280,6 +285,9 @@ class Application(ApplicationFactory, SingletonApplication):
         return backgroudColor.lightness() < 128
 
     def isDarkModeEnabled(self):
+        if SystemRuntime.flatpakID():
+            return self.isDarkMode()
+
         if not SystemRuntime.isAdmin():
             return AppSettings.isStateON_('DarkMode')
         else:
@@ -393,6 +401,13 @@ class Application(ApplicationFactory, SingletonApplication):
             else:
                 logger.info('not running from Linux AppImage')
 
+            flatpakId = SystemRuntime.flatpakID()
+
+            if flatpakId:
+                logger.info(f'running from Linux flatpak: \'{flatpakId}\'')
+            else:
+                logger.info('not running from Linux flatpak')
+
             logger.info(f'python version: {PLATFORM_PYTHON_VERSION}')
             logger.info(f'system version: {sys.version}')
             logger.info(f'sys.executable: \'{sys.executable}\'')
diff --git a/Furious/Widget/GuiTUNSettings.py b/Furious/Widget/GuiTUNSettings.py
index 3fdaab0..0f57fab 100644
--- a/Furious/Widget/GuiTUNSettings.py
+++ b/Furious/Widget/GuiTUNSettings.py
@@ -22,7 +22,6 @@ from Furious.Interface import *
 from Furious.Library import *
 from Furious.Qt import *
 from Furious.Qt import gettext as _
-from Furious.Utility import *
 
 from PySide6.QtGui import *
 
diff --git a/Furious/Widget/SystemTrayIcon.py b/Furious/Widget/SystemTrayIcon.py
index 5b1308b..39499e2 100644
--- a/Furious/Widget/SystemTrayIcon.py
+++ b/Furious/Widget/SystemTrayIcon.py
@@ -18,7 +18,6 @@
 from Furious.Frozenlib import *
 from Furious.Qt import *
 from Furious.Qt import gettext as _
-from Furious.Utility import *
 from Furious.TrayActions import *
 
 from PySide6 import QtCore
diff --git a/Furious/Widget/XrayAssetViewerQListWidget.py b/Furious/Widget/XrayAssetViewerQListWidget.py
index 263167e..61ba725 100644
--- a/Furious/Widget/XrayAssetViewerQListWidget.py
+++ b/Furious/Widget/XrayAssetViewerQListWidget.py
@@ -20,7 +20,6 @@ from __future__ import annotations
 from Furious.Frozenlib import *
 from Furious.Qt import *
 from Furious.Qt import gettext as _
-from Furious.Utility import *
 
 from PySide6 import QtCore
 from PySide6.QtGui import *
diff --git a/Furious/Window/AppMainWindow.py b/Furious/Window/AppMainWindow.py
index 1379f4f..3d1a1f2 100644
--- a/Furious/Window/AppMainWindow.py
+++ b/Furious/Window/AppMainWindow.py
@@ -22,7 +22,6 @@ from Furious.Interface import *
 from Furious.Library import *
 from Furious.Qt import *
 from Furious.Qt import gettext as _
-from Furious.Utility import *
 from Furious.Widget.UserServersQTableWidget import *
 from Furious.Widget.GuiTUNSettings import *
 from Furious.Window.UserSubsWindow import *