After having tried the numerous battery apps & widgets on the Android market, both free and paid for, I settled on Battery Indicator Pro by Darshan Computing. This app runs in the background with little noticible effect on battery life itself. It is not a widget, so it does not take up home screen space. Nor do you need to go find it in the apps drawer. It is visble in the notification bar as an addtional battery icon. The icon has a number in it representing the available percentage of battery left. In the options screen you can select the thresholds to change the color from green to white to red as the battery drains. I have mine set at the default of 100-70% left green, 69-30% left white, and below 30% red. At a quick glance you can tell how much battery is left and then adjust your usage accordingly. If you want some more information, you can swipe down the Notification bar and view the Battery Indicator info in the Ongoing Status section. The information displayed is Battery Left Percentage. Fully Charge, Charging or Unplugged since TIME. Battery Health, Temperature(Selectable Celcius/Fahrenheight) and battery voltage and time of last reading. Totally worth the price of 99 cents and the only way it could get better is to replace the built in battery indicator completely. Note for Built in: I have seen some custom roms with battery left % in them, but the display is so tiny you need a magnefying glass to read them. Not worth custom roming just for that.