LowPowerBanner is a tweak released today in Cydia that modifies the way iOS warns us when our iDevice runs out of battery. Normally iOS displays a warning message when this happens, the message having to be "accepted" by the user, the process repeating itself every time the battery drops below a certain level. LowPowerBanner comes to solve the problem by transforming that notification message into a Banner type message displayed exactly as you see in the image above. Basically, you will not see a window in the middle of the screen, but a banner only at the top, a banner that disappears by itself after a few seconds.
LowPowerBanner is available for free in Cydia and automatically changes the warning message as soon as it is installed. The tweak only works on iOS 5.x.