Ive personally circuit bent many of the SK series keyboards, and have been hoping for a plugin version for years now. This app executes it very well. Developers, a request I have is for a patchbay with some trim pots to route through as well as an LFO section with a robust mod matrix for targeting the bends and synth / drum voices. Really well done all around tho. Thank you!

I am quite pleased with this app. As of 04/2026, this app comes with 2 emulations, with more promised: a famous semi-modular synthesizer, and a circuit bendable 80s toy keyboard. I bought this app because of the toy keyboard: a couple of romplers exist with those sounds, but those cannot be patched to actually change the sound or to process your own samples. In this regard I have found this app to be excellent: the sound is close enough to the original to satisfy me. The app can be loaded standalone, reading from the onboard iPhone mic, as an auv3 instrument and also as an effect in a pass-through mode - this allows you to give any sound a “Lofi crunch” without even having to record it as a sample in the keyboard. I also appreciate the circuit bending playground, which lets you do things like bypass the aliasing filter, a common thing people do on the original and which provides a different timbre to the instrument. Also try turning on and off the speaker vs line out- this also changes timbre. Some people on the loopy pro forums were complaining about the UI claiming it to be too small: I found it to be pretty intuitive to use the zoom scrollbar on the side and joystick to move around in zoomed-in mode. I am satisfied with this, especially on the iPhone where apps are regularly tiny and unusable anyways (thank you for supporting both iPhone and iPad!!) but I can imagine it could be more frustrating trying to draw patch cable connections on the 2600 emulation and having to navigate zooming in and out while also doing that.I do think the app could benefit from a dedicated “change instruments” button, I agree with others on the forums saying that navigating using the back button in the preset browser until you select a preset for the other instrument is unintuitive. Overall, I think this is a very comprehensive emulation. I used to own the original toy keyboard and I can tell the developer took great pains to emulate even the small details of the original. The support for auv3 and using it as a sound processor makes it immediately useful inside auv3 hosts as a music making tool. I am very happy to have access to this on my phone and tablet, and excited for the potential of more future updates and additional instruments down the road.

iPhone 8. When selecting the preset tab, app freezes. It’s now impossible to select the other instrument. I’d consider this app broken as is. Hopefully I can update my review to reflect a more positive experience. Side note: The 2600 sounds good. I can’t access the SK1. Also, a pinch zoom is preferable to the slider/joystick combo, but I can tolerate it just because I’m so excited to see a 2600 on iOS.

It hangs when trying to change patches.