Quantum is a free Android app developed by Peak Pocket Studios that provides an easy way to monitor your phone's screen time usage. The app offers a screen time tracker that displays information on app launches, device unlocks, and received notifications. These data are available on a daily and weekly basis, allowing you to keep track of your usage over time.

With Quantum, you can visualize the duration and number of sessions you spend on your phone. The app also lets you control the time you spend on your phone and in which applications you waste it. This feature is great for improving your digital wellbeing.

It's worth noting that Quantum retrieves all its data from your Android terminal, which means that the data is private, and no one can access it. However, the app may not be 100% accurate and may still contain bugs.

In conclusion, if you're looking for a simple and effective way to monitor your phone's screen time usage, Quantum is definitely worth checking out.