most apps that claim to help with battery and/or task killers generally do more harm than good....i find the shift in particular has excellent battery life, especially compared to some other android phones running sense....the only app (well widget really) i recommend is the SMODA widget from the market....its just a simple one-click button to turn off mobile data (3g) when not needed...you can still make phone calls and send texts without 3g on [not mms though you would need to turn data back on], but of course if you want to browse the web or android market or something you would need to turn it back on....this will help with battery a lot...some other tips to help are to turn off auto-sync in the settings or at least lower the sync time so it doesnt do it as often, keep wi-fi, 4g and gps off when not necessary and keep your screen brightness as low as possible but you can still see the screen comfortably....also when the phone is searching for a signal that eats up a lot of battery as well and I recommend updating your PRL and profile to see if that helps or switching to airplane mode when youre in an area with bad signal for an extended period of time [of course you will have zero data or phone calls/sms this way....basically turns all the radios off].....other than that the only thing left pretty much would be to root which will allow you to do many things such as remove bloatware that sprint wont let you uninstall out of the box, install custom roms/kernels and overclock the processor undervolt the battery, all of which can have varying effects on battery life...hope this helped!