Grapes is a free iPhone app developed by Limit Point Software that serves as a comprehensive index of scales for guitarists. Unlike other guitar apps, Grapes offers a simple and accessible display without unnecessary complexity while still providing an extensive collection of scales.

One of the standout features of Grapes is its "Modes" section, which allows users to explore and visualize each mode's unique shape. By tapping "view," users can open up the mode on the fretboard and gain a more complete understanding of the entire scale or mode.

The app includes all 28 modes derived from the 4 heptatonic scales: Major, Melodic Minor, Harmonic Minor, and Harmonic Major. Additionally, it offers the Pentatonic scale and its modes, as well as 5 symmetrical scales. With its horizontal fretboard display, guitarists can easily navigate and learn these scales.

To prevent screen lock, Grapes also includes a useful capability that ensures uninterrupted practice sessions.

Overall, Grapes - Scales for Guitar is a valuable tool for guitarists of all levels, providing a straightforward and comprehensive resource for learning and exploring scales.