Using Clean Master from when I got my first android device. it is the best app for cleaning android phone.in this long journey it became better an better.with lots of feature like Cleaning leftover files, Duplicate photo remover, Antivirus, App manager, Ram Manager, App Locker and more. you can also backup android apps via Clean Master if you are Rooted and the most amazing Feature I like is Hibernating apps this this app is a ultimate in protection and features. and all these features lets you save your battery too.