I designed these little doodads to do exactly what the title says...I wanted something to hold my phone for sampling or MIDI out, as well as something to angle up the OP-1 a little bit. So I worked up a few prototypes and printed them. I came to the final design you see here...https://www.thingiverse.com/thing:2731518
They're free to download and 3D print. If you don't have a 3D priner, there are online services, or if you ask around you might know someone who has one. Also, many city libraries have 3D printing service. Worst case scenario, here's an excuse to buy a small cheap one. They've gotten REALLY cheap and really good.
I posted these on a Facebook OP-1 group, so some of you might have seen them already.