Fret Tester is a comprehensive fretboard trainer designed to help you learn music on guitar, mandolin, or bass. Developed by educator William Wilson, the program covers everything from note names on the fretboard to reading standard music notation. With a user-friendly interface and clear buttons, Fret Tester offers four modes of play including Name Note, Find Note, Notation, and Notes on Staff. You can choose from four different instruments - Guitar, Bass, Mandolin, and Five-String Bass - and track your progress with instrument and game statistics. The app also features fretboard charts, custom tunings, left-hand mode, and HD graphics for an immersive learning experience.