The Montal Tuner is a software piano tuning aid specifically designed for use by blind piano tuners. It was derived from the TuneLab Piano Tuner software for iPhone. Montal Tuner is named after Claude Montal (1800-1865), the first famous blind piano tuner.
In the Montal Tuner, the tuning indicator is a sweeping tone that sweeps up in pitch to indicate sharp and down in pitch to indicate flat. To keep this sweeping tone separate from the microphone input that is supposed to be listening to the piano, it is recommended that the Montal Tuner be used with external headphones rather than with the built-in speaker in the device.
Montal Tuner is divided into the Main Tuning screen, where all the tuning happens, and the Settings screen, where the configuration, setup, and all other functions are done. Both the Main Tuning screen and the Settings screen have a large button on the bottom that will return you to the other of these two screens. These buttons are large enough to easily find by feel without having to scroll through all the items on the screen. The two-fingered Zee-gesture will also toggle between these two major screens.