When some chat tools receive APK files, they will add .1 after the file name for security reasons, causing the system to be unable to recognize it as an application installation package. This application intercepts the apk.1 suffix to avoid the problem that users need to modify the file name after downloading to install.
In 8.0 and above, you need to allow the app to install other apps.
Source code: https://github.com/twiceyuan/WXAPK