Train your ear! Instead of relying on visual tuners to tell you when your "in tune", use just your ear, and these simple drones which you can compare your singing, or instrument. This app may appear confusing, but spend a minute or so reading the dialog boxes and you will have good ear training, and music practice tools at your hands. You can come to understand what it actually sounds and feels like when your in or out of tune (sometimes you want to be a little "out"), and what intervals sound like together. Capabilities include complex sine wave drones for each of the twelve pitches, just tuned perfect fifths on each pitch, fine interval tuning, and a metronome that can play polyrhythms. Be careful not to overload the app by triggering too many things at once. The app is extremely small in size, only a couple of megabytes, because it doesnt play audio clips, but generates sound!
This app was built on the RTcmix engine which was developed by the RTcmix community ( www.rtcmix.org), thanks to Brad Garton, Damon Holzborn, and others who made this possible. I would be happy to offer how I built this app to those who are interested.