iPhone's battery is disgusting. So let the Battery Plus monitors your iPhone battery usuage and extend your iPhone battery life.

Battery Plus is a powerful battery management application specially designed for iPhone and iPod Touch. As the name tells, it is by far the most powerful battery management application on iTune store.

Battery Plus
automatically detects the type of your device (it differentiates between iPhone 3G, 3GS, and iPod Touch generations) and its active network (Edge, 3G, or Wi-Fi). Based on system specifics, Battery Plus then provides the most accurate information on your battery charge, which includes:
1. Remaining talk time, audio time, video time, and internet/data time
2. Current battery capacity
3. Charge time left to full capacity
4. Your battery’s charging cycle (An accumulated 100% charge is counted as 1 charging cycle), which helps you track your battery’s usage and decide when it needs to be replaced.

Really very powerful.