The application identifies notes in the range of minor, single-bar and double-bar octaves. In the MIDI directory it is the C3-C6 range. The tuner tolerates quarter-tone deviations from the nominal frequency. Eight notes of one octave are shown on the screen. Octave ranges are set automatically according to the pitch of the note that is currently being played or last played. The current range is shown by the header icon on the right. Two screens can be used to display tones, switched by swiping h