Guitar Chords Scales Master is a free iPhone app developed by Loop-Sessions.LLC. It falls under the Multimedia category, specifically Music & Radio. This app allows users to smoothly switch between play modes, such as stroke or choking. Users can also play with the chord tone of a specified code only in stroke mode. The app supports an open 22-fret fingerboard and enables users to play with multi-choking. Additionally, it supports switching of the left hand.

To use the app, users can register the chord or scale they want to display from a selection of 53 types of chords and 21 types of scales. When a registered chord or scale is selected, the corresponding chord tone mark is displayed on the fingerboard. Sliding or stroking on the fingerboard will play a chord tone close to the tapped position.

It's worth noting that some advanced features, such as displaying all chord patterns including tension, require an In-App Purchase.

The app also provides a comprehensive list of chords and scales, including major, minor, augmented, diminished, sus4, and various extensions.

The developers have plans to update the app in the future, including adding more guitar types, effects, and unusual tunings. Users are encouraged to provide feedback and suggestions for additional features they would like to see.