A supposed fix to the iPhone 4S' battery life issues is on the way from Apple, but until the update is officially released to the public, Philips has stepped up to the plate with a useful app that will help you maximise the battery life on any iOS device.
While it doesn't do anything magical like harness the power of the sun or your positive chi to prolong battery life, it does provide detailed reports on how long your device will keep running given its current charge level and how you intend to use it. The app's main screen prominently displays the current battery charge as a percentage, with a series of buttons showing you the estimated time remaining for a variety of common activities like calls, playing audio or video, gaming, and even standby.
And besides providing recommendations and suggestions on how to tweak your settings to maximise battery life, a "What if" feature will actually give estimations on how long the device will run by changing various settings. Or, you can tell it how long you need the battery to last, and it will provide a list of things you can do, like decreasing the backlight intensity, turning off Wi-Fi etc. to reach that goal.
The BatterySense app is provided as a free download to iDevices running iOS 3.2 later, and I can't help but wonder if 'turn off this app' is listed at the top of its battery saving suggestions.