Use APKPure App
Get App Killer old version APK for Android
Helps you save your battery by killing those apps that don't need to be running.
OK on Android 1.6 (version 4) and upwards.
No tricky permissions, no trip wires, no data farming, no internet connection, no ads, no contact gathering or phone permissions
This app is very effective and useful for stopping apps that drain memory and battery!