A tripod adapter for mounting an iPhone 7/8 Plus in an Otter Commuter case. Capable of holding the phone in portrait or landscape thanks to the tight fit, would not use in portrait orientation without the case on the phone. The mounting hold has a 1/4-20 UNC thread to attach onto a standard tripod mount.
If your phone doesn't have a case, use some thick rubbery tape, like electrical or hockey, to make the inside of the mount grip the caseless phone.
I actually used Glow-in-the-dark green because it's a quick print and that's what was in my printer, so pretty much anything should work for this design.