Is there any good battery saving apps for jb?
I've tried almost all the battery saving apps and none of them proved to have a noticeable difference. In fact some of the apps interfered with the use of the phone and caused it to go "rogue" sometimes and ended up killing my battery even faster.
The best way to save battery is to do it yourself. Turn off any notifications you don't really need or at least change the interval, use Wifi whenever possible, don't check your phone every 5min, etc.
I found that doing it yourself yields much better results than relying on an app that can conflict with your phone's functions. And if you want a real boost in battery, flash a ROM on that sucker and try out a different kernel as well.