gStringX is a fun, colorful, visual reference for musical scales, modes and arpeggios, for guitar and keyboard. It covers Major, minor, & Dominant arpeggios. Major scale and modes. Harmonic minor scale and modes. Melodic minor scale and modes. Double harmonic Major scale and modes. Messianen modes. Exotic scales and more. Displays information for Guitar and Keyboard in any key. Colorful display options. Large display for easy viewing while playing your instrument.