Android battery saving appliaction

1) i want the app to show available battery percentage of device 2) The app should show active app and what is the battery consumption by those apps 3) i want a kill switch which will terminate all background apps. 4) there should be a notification with alert when battery level drops to 15% also after battery level drops to 15% the mobile data should be switched off and screen brightness should be reduced 5) layout should be very preeti look experience must