I wanted to like this tripod/mount holder a lot!
It has one of the cleverest ways to expand it's size that I've seen, as a tinkerer, I was quite impressed.
But, other details muted my excitement pretty quickly.

It's trick is that Initially it's sized for a phone, but by pushing buttons on either side and pulling slightly out on the arms, they'll extend a bit more than an inch on each side, making it just large enough for a tablet if you clip it on the short sides.

The springs are very strong, which is great. I hoped I could use this beyond the normal phone/tablet expected, because I often use these to hold music gear, small synths, pedals, controllers, etc. But, even though the spring would hold it, I'm afraid the lip/edge where a device is grabbed is set up in a way that won't even fit my phone as I would expect. I put a case on my phone recently that has one of those rings that work as a stand, or help you hold the phone. And it sticks out far enough on the back that it keeps this holder from being able to get around the edges of my phone.

Bummer, because I like it a lot otherwise. Maybe I can find a way to put something over the edges that will still be secured. Maybe they'll update the version to have a wider gripping edge, If they do I hope I notice.