Use APKPure App
Get Apk Extractor (App Backup) old version APK for Android
It can extract any app weather its paid or not.
APK Extractor will extracts APK which is installed on android device and copy to SD card.
★ Fast and easy to use.
★ Extracts all most all application,includes system applications.
★ ROOT access only required for extracting paid apps.
★ Apk's will be saved in /sdcard/Download/Eimon/.
★ Provided Search option to search applications.
★ Compatible with latest version of Android 6.0
★ Saved apk format : AppPackageName.apk.