This is a universal clamp to use a phone with a standard tripod camera mount.I couldn't seem to find one of these so I just made one for myself. I also used the opportunity to try out a new thread mechanism I was toying with.
This design features angled clamping surfaces that don't interfere with the volume buttons (on my phone). The base also incorporates a spring-loaded jaw for smoother tightening on the phone, adding wax from a candle / soap bar makes tightening smoother as well.
See it working:
Additional parts needed:
-1/4-20 size nut for the tripod attachment
-wax to put on threads