CustoMIUIzer is a helpful Android app developed by Mikanoshi that contains a variety of Xposed mods that extend the functionalities of MIUI devices. The app is free to use and falls under the category of Utilities & Tools. It is designed for MIUIon Android 9-10, and its functionality is not guaranteed on other versions, especially lower MIUI versions. The app requires (Ed)Xposed Framework installed, and its APK installation is limited to Android 7+.

To use CustoMIUIzer, enable the module in (Ed)Xposed Installer, reboot, set up the mods you prefer, and select 'Soft Reboot' from the menu. The app supports settings backup and restore using local backup on SDCard/internal storage, and it also offers automatic Google cloud backups via the Android Backup Service. You can send a detailed report with a description of your problem from CustoMIUIzer itself or create a new issue on the issue tracker.

Overall, CustoMIUIzer is an excellent app for MIUI device users looking to extend their device's functionalities. However, it is essential to note that the app only works on specific versions of MIUI and Android, and its compatibility with other devices is not guaranteed.