update app manager page

docs/app-manager.mdx

@@ -6,24 +6,34 @@ sidebar_position: 6
 
 App manager lists installed apps on device.
 
-## App Types
+## Filters
 
-The app type filter has 3 options:
+There are several filters to help you find the app you want:
 
-* **System apps**: apps that are pre-installed on the device and can't be uninstalled.
-* **Third-party apps**: apps that are installed by the user.
-* **All apps**: both system apps and third-party apps.
+* **System App**: show only system apps or third-party apps. System apps are the apps that come with the device and can't be uninstalled.
+* **Can be launched**: whether the app has a main activity that can be launched. Apps that can be launched are usually the ones you can see on your home screen or app drawer.
+* **Can be backed up**: whether the app supports the legacy backup feature. Most apps don't support backup, and this filter is only useful for a few apps.
+* **Split APK**: whether the app uses split APKs. This will affect the behavior of the **Export APK** function.
+
+Each filter has three options:
+
+* **Not Matter**: the filter is not applied. All apps will be shown.
+* **Yes**: only apps that match the filter will be shown.
+* **No**: only apps that don't match the filter will be shown.
+
+If multiple filters are in **Yes** or **No** state, only apps that match (or not match) all filters will be shown.
 
 ## Install APK
 
 If you have an APK file on your computer, you can install it on the device by clicking the **Install APK** button.
 
-Multi-part bundles are not supported. This includes `.apks`, `.xapk` and `.apkm` files.
+It can also install split APKs, including `.apks`, `.xapk`, and `.apkm` files.
 
 ## Command bar
 
 The command bar has the following buttons:
 
 * **Uninstall**: uninstall the selected apps. It's disabled for system apps.
 * **Backup**: create a backup of the selected apps. App Backup is a deprecated feature, and most apps can't be backed up. For apps that allow backup, the backup file will contain the app's data, settings, and optionally the APK file.
-* **Details**: show details of the selected app. This contains a breakdown of the app's storage usage.
+* **Export APK**: export the APK file of the selected apps. The APK file can be installed on other devices. If the app uses split APKs, the exported file will be a `.apks` file including all installed features.
+* **Details**: show details of the selected app. Including a breakdown of the app's storage usage.