A nifty homage to an innovator and an obscure inventor
Probably the only iPhone application that pays tribute to a former Soviet secret agent (he was kidnapped from the United States by the GRU/KGB/whatever it was called back then, and the circumstances of his death are still lost in the fog of the Soviet Union), it offers the average Joe a chance to experiment with a musical Instrument that was once written for by serious modern composers like Varesé.
While the chromatic setting offers you more control, you should keep it set on the default for authenticity. Ditto the vibrato - sometimes its best not to try to improve on the original. And the animation of the inventor in icing on the cake.
Mind you, its not the real thing. But, as someone already said, at a thousandth of the price (and weight), the cost to you makes this a bargain route to ownership of a piece of music history.
Sensha about
Theremin