Timeslicer is an iPhone application developed by Christopher Gross that serves as a practice tool for polyrhythms. It allows users to feel and count smaller even beats within two rhythms, helping them understand and master polyrhythmic patterns.

The app provides a visual representation of the beats, allowing users to set the sounds, rhythms, and tempo they want to practice. Users can then listen, watch, count, and feel the beats, tapping along on the buttons at the bottom to keep the beats orange and continue their streak.

Timeslicer also offers preset exercises that range from simple to more complex patterns, serving as a guide for users to progress in their polyrhythm practice. The app encourages experimentation, practice, learning, and play, providing a versatile tool for musicians and music enthusiasts alike.

Please note that while tapping along to a clockwork-like rhythm may not be the most musical activity, Timeslicer offers a unique opportunity to challenge oneself and explore the intricacies of polyrhythms.