I find treadmills extremely boring, but it's can be a good way to get exercise. To help pass the time, I like to put youtube videos on while I'm running, but there's nowhere convenient to mount my phone.
This holder is designed to clip onto the vents at the top of the (pictured) treadmill and give a place for the phone to sit. The supports are far enough out that there's space for a phone in a wallet-style case.
I've included three different sets of “legs” that hold the back at a different angle. I use the “Tall Person” variant, but there is also a “Short Person” one (with the phone screen angled down a bit) and a “Very Tall Person” one (with the phone screen angled further up). I must admit that these versions came about as I was gradually tweaking the design to get the phone to point at my face!
The author hasn't provided the model origin yet.