A free program for Android, by A4tune Labs.

Tuneo is a very versatile tuner for any type of instrument. It is the best solution for people that want to tune their guitar, violin, bass, ukulele, viola, cello, banjo, shamisen, or any other instrument. The best thing about this app is that it is extremely accurate. The best thing about this app is that it works for many instruments, like guitar, violin, bass, ukulele, viola, cello, banjo, shamisen. You can also use it to tune by ear. Tuneo supports many types of music, like classical, jazz, pop, rock, and blues. You can also use it to tune by frequency. It is very easy to use. You just have to press the button that plays the reference tones, and you can tune your instrument accordingly.