iControl is a new app in Cydia that manages the state of your Bluetooth, WiFi, 3G and 2G radios to maximize battery life of your iPhone. It also extends the battery life by allowing you to designate applications that iControl should kill after you lock your iPhone.
Once you’ve configured your preferences, i.e. you would like Bluetooth, WiFi and 3G on only when your iPhone is unlocked (or charging too) and the rest of the time you would like your iPhone to leverage the battery saving 2G mode, iControl will do this every time you unlock/lock your iPhone. By ensuring that you use only the fastest battery sucking radios like Bluetooth and 3G when you need them, iControl will extend the battery life by up to 100%.
Note: Requires iOS 4.0+
iControl is available in the Cydia Store via BigBoss repository for $4.99