APK.1 安装 is an Android application developed by twiceYuan. It is a free utility tool that solves the problem of unrecognized APK files by intercepting the apk.1 suffix. The app eliminates the need for users to download and modify file names before installation.

The app is particularly useful for users who receive APK files through WeChat, as the platform adds the .1 suffix to the file name for security reasons, making it impossible for the system to recognize it as an installation package.

It should be noted that on Android 8.0 and higher, users will need to allow the app to install other applications. The source code for the app is available on GitHub for those interested in viewing it.