DU Battery Saver & Widget is a productivity app whose main functionality is to extend the mobile device's battery life.
Functions:
It has three preset modes to optimize the battery use: general mode, focuses on the basic functions; long wait, closes all activities except calls and SMSs, night mode, closes all activities except the clock.
Activities:
The user can customize the battery indicator: in the status bar, and it gets red when battery power reaches 20%, and the program sound to alert you when the battery is running low.