The Justin Guitar Fretboard Note Trainer is an Android app designed to help guitarists learn the notes on the guitar neck. It offers four different training modes, including Name The Note, Find A Note, Memory Quiz 1, and Memory Quiz 2. The app also includes some "Easy" options for beginners to limit the range of answers.

One of the most interesting features of this app is the audio option, which allows users to hear the notes as they select them. In addition, the app offers a cheat option where users can swipe their finger diagonally across the fretboard to see all the notes for a second.

Overall, the Justin Guitar Fretboard Note Trainer is a great app for guitarists looking to improve their skills. With its fun and progressive games, users can play and learn anywhere, anytime.