If what you really need is a typical TB303 sound in your iOS set up, then you may have just found exactly what you’re looking for. If it really isn’t anything that’s going to set your heart all a flutter then perhaps skip to something else for now. I know that for some the classic sound of the 303 is a big deal. Personally I found them awful to program and limited, so anything that anyone can do to make the sound without the issues of the original is a good idea in my book. Having said that, I’m not sure of too many situations where I’d want to use one right now.
However, if it’s what you want then 2XB303 could be just right. Here’s everything that the developer says about the app including all of the relevant iOS specs:
“A creative bass synth sequencer for electro melodies or dirty phat & funky acid techno basslines. Look at the video tutorial for a how-to guide. Listen to what you can create easily with 2XB303. With sequence manipulation features, effects, external syncing & audio routing. Inspired by the acid house music scene. An IOS exclusive. Create sequences using standard step functions as seen on various sequencers like the Roland SH-101 or use one – button generation. Sound tweaking by familiar means: filter cut-off & decay Env-Mod & glide & accent etc for those classic sweet-spot acid growls.”
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.