Completely Brilliant! Being new to android, I couldn't figure out how to use this app. I wrote to the developer, Martin Steiner, who wrote back quickly sending me a custom-made page of screen shots with red arrows and instructions showing me exactly how to get the calculation that I wanted. This app is BRILLIANT ! Martin is BRILLIANT ! I'm extremely impressed (and grateful) that he would go to this much trouble for an individual user. Michael (bassoonist, Toronto Symphony Orchestra).