TuneWave

Sleek, efficient, and responsive, TuneWave is the no-nonsense utility that lets you tune your instrument quickly and easily. TuneWave puts everything you need front and center for optimal visibility and glanceable feedback. It can transpose if you’re using an instrument that requires it, and it can even adjust the base frequency to fit your needs. You can even adjust the input volume based on your instrument or surroundings for the best possible results. Forget big dials and fake wood, just get in, get ready, and then get back to your music.
"the design is modern and the app has few distracting bells and whistles...minimalist and speedy." - The New York Times