diff --git a/various-tools/Asset preloading flutter app/server_checker/README.md b/various-tools/Asset preloading flutter app/server_checker/README.md
index 5fc2d95..d94657f 100644
--- a/various-tools/Asset preloading flutter app/server_checker/README.md	
+++ b/various-tools/Asset preloading flutter app/server_checker/README.md	
@@ -4,17 +4,25 @@ This is a flutter app for batch downloading GC2OS server assets (music and chart
 
 To use it, you need to
 
-1) Compile the project to .apk or .ipa,
+1) Compile the project to .apk or .ipa. learn how to [here](https://docs.flutter.dev/deployment). A pre-compiled apk is provided, it has the same name and signature as the 4max version apk.
 
-2) Sign the package to match the game client exactly (so you can install/sideload them and have them share the resource folders),
+2) Sign the package to match the game client exactly (so you can install/sideload them and have them share the resource folders), this is general android/ios knowledge, use apktool + common certificate or a common ipa signing service.
 
-3) Install the package,
+3) Install the game. Then, install the package on the device,
 
-4) Generate a `batch_token` in the database through some means (database edit, discord bot, etc.)
+4) Generate a `batch_token` in the database through some means (database edit, discord bot, etc.). The schema of the table is as follows: 
 
-5) Open the app and enter the server base URL and token,
+- id: auto generated primary key, ignore
 
-6) Click download and wait!
+- token: The key string itself. Required field
+
+- expire_at: Unix timestamp integer of the expiration time. Required field.
+
+- sid, verification_name, verification_id: Not required in the public version. Fields for bots to link with 3rd party accounts.
+
+5) Open the app and enter the server base URL and token, click download and wait!
+
+6) Once done, install the game pack.
 
 This is a beta solution. Please report issues and errors.
 
diff --git a/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk
new file mode 100644
index 0000000..1b71203
Binary files /dev/null and b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk differ
diff --git a/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1 b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1
new file mode 100644
index 0000000..6ea4d76
--- /dev/null
+++ b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1	
@@ -0,0 +1 @@
+07e3ccb23568eac4c695ea7c08e5679f3c696ac5
\ No newline at end of file