Save iPhone Battery With ScreenDimmer Cydia App
Your iPhone’s auto lock feature is a great way to save battery. However sometimes you are in the middle of something important, and suddenly the screen is locked. Very irritating, isn’t it? What if you could have more control on when to trigger the battery saving mode?
ScreenDimmer, a $0.99 Cydia app, saves battery on your iPhone by automatically dimming the screen, after a set period. The best thing is that you can add a list of ‘Excluded Apps’, thus ridding you of any annoyances you earlier had with the native iPhone auto lock. Once installed, you can access ScreenDimmer’s options from the Settings screen. Here you can turn the app on, turn on/off Backlight, set the delay timer for the dimming, and so on.
In order to install this app, you need to first jailbreak your iPhone.

it doesn’t let you have your screen dimmed while it’s charging. i really don’t like that cuz when i have my ipod charging, and i have the screen on cuz im doing something on it, it gets very hot. i really hope they add this feature.