A440 Tuner

A440 Tuner is a simple app for musicians who prefer to tune by ear to a reference Concert A (440Hz). Choose between a recording of a real oboe or a synthesizer oboe.
This app is not a meter or strobe or chromatic tuner - it simply produces the Concert A reference pitch.
While this may seem limited from the viewpoint of one who usually tunes by meter, it fits the needs precisely for musicians who are trained to tune their instruments by ear from a reference pitch.
The oboe was chosen for this app because in an orchestra setting it is typically the oboe that gives the reference pitch at the beginning of rehearsals and concerts.