The original https://github.com/skylot/jadx

This tools used old version cause newest version is not possible to run in android api 21

How to use

First install to your device

git clone https://github.com/Lexiie/Termux-Jadx 
dpkg -i ./jadx-0.6.1_all.deb

jadx --deobf yourfile

Extension Support Apk/Jar/Dex/Class