Fretboard Visualizer is an app for visualizing music scales and chords on a guitar, bass or a ukulele fretboard. Select a scale and/or a chord and the app will highlight the notes on the fretboard accordingly.
After selecting a scale you can see which notes are in the scale, as well as toggle through the different positions of the scale. You are also shown a list of chords that fit with the selected scale.
Each chord has multiple voicings which can also be toggled through and the notes which make up the chord are listed as well.
Fretboard Visualizer supports guitar, bass guitar and ukulele and several most common tunings are provided along with the feature to change the number of frets on your instrument.
Rotating your phone will show the entire fretboard at once.

Chords:
maj, min, aug, dim, 5, 6, m6, 7, maj7, m7, dim7, dim7b5, sus2, sus4, 7sus4, 9, maj9, m9, add9, 11, maj11, m11, 13, maj13, m13.

Scales:
major, minor, major pentatonic, minor pentatonic, major blues, minor blues, lydian, ionian, mixolydian, dorian, aeolian, phrygian, locrian.

Tunings:
Standard, dropped and open chord tunings