Game killer app makes playing game more fun and entertaining. Go ahead and download and install game killer apk latest version from the link provided below.
Once downloaded make sure to transfer the apk file from your PC to android device and then turn on unknown sources settings as well.
Note: In case your device is not rooted make sure try to be safe installing the app as it may break your device warranty. So incase you are sure that your device may be rooted and you are aware of the process of replacing ROM and root process then you can go ahead.