Application could show notes from chromatic scale where A=440hz. It could be used for tunning such instruments as gutar, violin, piano and others. "Chromatic Guitar Tuner" also helpful for learning bends. Application uses microphone to show playing notes and deviation if its not clear. Its beta version but If you think this application isnt good enough please let me know and Ill fix it or add new feautures! I am happy to help you. Thanks!