Battery Cycle is a free Android app developed by PlusTwo that provides you with detailed information about your battery's status. The app is compatible with Android 9.0 and allows you to keep track of your battery usage cycle, capacity, temperature, and status.

With Battery Cycle, you can monitor your battery's health and assess how much it has been used, making it an excellent tool for second-hand trading. The app also helps you determine when it's time to replace your battery by giving you access to your battery's capacity.

However, it's worth noting that this app doesn't support Android 10 OS, and some of its features may not be available on certain devices. If you're experiencing quick battery wear, Battery Cycle is an app worth checking out.