Rap Beat Maker - Freestyle Hip Hop is a free Android app developed by Peter Khlopenkov, falling under the multimedia category, more specifically, music and radio. With this app, users can create unique beats with ease using up to six instruments. The app offers 30 unique samples and patterns, with over 1.2 billion different combinations possible. One of the most significant advantages of this app is that it is ad-free.

The app's interface is user-friendly, with the main screen displaying a default beat, which users can play by pressing the play button. Users can mute/unmute an instrument by clicking on it and scroll through available tempos by pressing the tempo button. The app also has a randomize feature that gives users a unique, professional-sounding beat. To customize a beat, users can hold on the instrument they want to customize, select a sample from the sample list, and choose a pattern from the pattern list, with pattern complexity increasing with pattern number. Users can select another instrument and use the back button to return to the main screen.

Overall, Rap Beat Maker - Freestyle Hip Hop is an excellent app for beat enthusiasts. The app is easy to use, has various customization options, and is ad-free.