BatteryBot is the original battery indicator app for Android, released in 2009 as simply "Battery Indicator". Both the free and the Pro versions have maintained a 4.5+ star rating in Google Play from the beginning. It offers two modes: the original status bar indicator and now also a desktop widget. You can use either or both, as you please.
Try the free version today! It requires NO special permissions whatsoever, and if you don't need any bells and whistles, it's an excellent and complete solution to your battery needs.
For those who want more than is offered in the free version, or for those who just like to support small, independent developers like me, the Pro version remains lightweight while packing in many useful features:
BatteryBot monitors and shows your batter