Decompile an app

Install APK Extractor

Download link : APK Extractor

Run APK Extractor

Use it to extract the .apk of your file
Download the APP_NAME.apk on your computer

Download dex2jar

dex2jar

Download link

Use dex2jar

• decompress it
• use the command

path/to/dex-tools-2.1/d2j-dex2jar.sh APP_NAME.apk

• use d2j-dex2jar.bat for Windows

APP_NAME-dex2jar.jar will be created

Download jd-gui

jd-gui

Download link

Use jd-gui

java -jar jd-gui-1.6.6.jar APP_NAME-dex2jar.jar

• Now you can see classes and save them