Tuning fork

This simple application is intended first of all for those musicians
who like to tune their instruments relying mainly on ears rather than
using various modern tuners with visual indication, or for all who
needs a reference musical tone for any reason. It produces an audible
reference tone by demand just like a classic tuning fork, and, being
installed on a smartphone, is always ready to use.

* Prepared for publication on F-Droid