Android application package (APK) is the package file format used to distribute and install application software onto Google's Android operating system.
This site uses a perfect open-source APK and DEX decompiler called Jadx: https://sourceforge.net/projects/jadx/files/ Jadx decompiles .class and .jar files, but also it produces Java source code from Android Dex and Apk files.
Please, only use it for legitimate purposes.
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