KeyFur is a free Android application developed by Tyler Rusk, designed to help musicians find the right notes and scales for their songs. This app is perfect for those who may have trouble identifying key signatures or want to explore new tonalities. KeyFur lists out the possible keys that the song could be in, allowing the user to select a key and see the scales associated with that key.

KeyFur shows the Ionian (Major), Dorian, Phrygian, Lydian, Mixolydian, Aeolian (minor), and Locrian scales. The app capitalizes the major chords that can be played with the notes and lowercases the minor ones, while the symbol for the diminished chord is º. It is simple and functional, without any ads or splash screens, making it easy to use and perfect for songwriting.