The Ultimate App for Power Users and Developers
If you want to try-before-you-buy, check out "Battery X".
COMPATIBLE WITH IPOD TOUCH AND IPHONE 3.0 (AUTO-DETECTS DEVICE)
Have you ever wondered, "How long can I play this game before my battery runs out?" or "How much talk time do I really have?"
This battery app is the end-all be-all of battery apps. It lets you log your battery usage and track it over time. That way you can truly see how much battery you're using.
Predicting battery life is always a game of approximation. That's why Battery X lets you act like a scientist and actually measure battery usage over time.
If you really want to get the most out of your battery, this is the app for you.