12 Simultaneous Visual Strobe Tuners for any musical instrument, fast, accurate, and noise resistant, using the built-in mic on your iPad. The multiple unique high contrast waterfall strobe visuals will quickly display the tuning in any of 12 note pitches and harmonics simultaneously. With 12 simultaneous strobe tuners, you don't need to wait for your room or recording studio to become quiet enough. You don't need to wait for a tuner to lock onto each note. You don't need to wait for a needle to finish moving. If you're really good, you don't even need to tune one note at a time. With multiple strobe tuners, you can see if one pitch shifts in frequency while tuning another. You can also see if plucking a string hard on a guitar causes the notes to "bend". Just watch the waterfall waveforms overlaid on each string. When the waves for a particular note synchronize or line up vertically, and stop leaning or shifting left (flat) or right (sharp), you are precisely in tune with an internal equally-tempered digital oscillator. If you are not sure if you understand using a waterfall strobe tuner, please download the Free inTuna A440 app from the App store (which can only tune 1 note: concert A = 440 Hz) and give it a try. For custom intonations, you can individually vary the reference frequency of each string in 1 cent increments up to +-30 cents away from equal temperament. The A440 reference is also adjustable. Notice: This app plays no piano sounds! It only allows you to visualize pitch from the microphone input.