Billiards Calculator by TS Yoon is a free Android app designed to help billiards players calculate frame points and angles using the Five and Half system. The app is a useful tool for both beginners and advanced players who want to improve their gameplay.

The app requires users to set the cue ball position and the 3rd cushion rail point to calculate the 1st cushion frame point. The app also provides information on where the ball is heading (frame point) and where it touches (rail point). Moreover, the app allows users to calculate the Plus system and Inside angle system (Short-Long-Short).

One of the app's unique features is that it adjusts the angle based on the cue ball position. If the cue ball position is less than 50, the angle becomes narrower, while if it is more than 50, the angle opens up.

Overall, Billiards Calculator is a helpful app for billiards players looking to improve their gameplay. It's easy to use and provides accurate calculations for frame points and angles.