Use APKPure App
Get APK Backup : APK Share : App B old version APK for Android
APK Extractor will extracts APK that are installed on your android device
APK Extractor will extracts APK that are installed on your android device and copies them to your SD card.
* Fast and easy to use.
* Extracts almost all application,including system applications.
* No ROOT access required.
* By Default Apk's will be saved in /sdcard/Downloads/myapk/.
* Compatible with latest version of Android 6.0