JADX - JADX is a decompilation tool that can produce Java Source code from Dex and Apk files, being capable of providing human-readable java classes, it reverses AndroidManifest.
APK Editor Studio - APK Editor Studio is an open-source Android application editor that allows you to edit APKs with the help of reverse engineering.
APK Studio - APK Studio is an open-source Integrated Development Environment that allows you to recompile and decompile Android applications with its unified interface.
Xposed Framework - Xposed Framework is an application that allows you to tweak and modify the Android system behavior without making changes to system apps.
JEB - JEB is an Android application decompiling tool that allows you to inspect and modify APKs.
ShowJava - ShowJava is an app that allows you to decompile JAR, APK, and Dex files for Android OS.