I like Theremin apps, and this one looks lovely.
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Theremin I/O turns your iPhone into a touchless music instrument. It uses your camera and flash to measure the distance to your hand, this signal is then processed by a synthesizer to generate a tone.
- Old-school synthesizer
- Constrain input to scales (harmony quantization)
- 8 sound presets with effect controls
- 50+ scale presets
- Use as a MIDI controller (requires in-app purchase)
- Learn fast with the tutorial overlay
It’s priced at $1.99. Introductory price during the first week!