iPhone Screenshots


Play with light – 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

For more information visit http://theremin.io

What’s New

Version 1.3

* Updated for iOS 11
* Network MIDI is now free!

Ratings and Reviews

4.0 out of 5
5 Ratings

5 Ratings

hiuhhseee ,


I have no access to change sounds. The bottom shows up for half a second and then goes blank. Where do I change sounds? Pretty cool how it works though. It’s awesome. Just love to have other sounds.

KDKnopp ,

Awesome simulation!

The GUI is top notch. Way above other apps that try to mimic the theremin.

Very customizable and well worth the small cost.

††The One And Only Warren Cain†† ,

Incredibly cool

Functions perfectly! The light sensor functionality is virtually flawless and the sound presets sound beautiful! It's really cool controlling the sound just by moving your hand closer or further away from the iPhone. You can also manually adjust vibrato and delay for added customization. In addition, they give you around 70 unique scales to choose from, and an option to just use the whole keyboard! It's one of my favorite apps!


FFFF00 Agents AB
18.3 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad Pro (9.7‑inch), iPad Pro (9.7-inch) Wi‑Fi + Cellular, iPad Pro (10.5‑inch), iPad Pro (10.5-inch) Wi‑Fi + Cellular, and iPod touch.



Age Rating
Rated 4+
© FFFF00Agents AB
In-App Purchases
  1. Network MIDI $5.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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