APK.1 安装

When WeChat receives an APK file, adding .1 to the file name for security reasons will prevent the system from recognizing it as an application installation package. This application eliminates the need to modify the file name to be installed after downloading by blocking the apk.1 suffix.

Above 8.0 you need permission to allow the app to install other apps.

Source code: https://github.com/twiceyuan/WXAPK