TempPiano is an app that can be confirmed three temperament at the same time.
TempPiano is an app that can be confirmed three temperament(equal temperament, just intonation, Pythagorean) at the same time.
You can also change A pitch, base tone, and volume.
The free version only work for 30 seconds after starting the application,
The paid version work unlimitedly.
To know how to use, please refer to the youtube video.