A simple Nexus 7 (2013) mount that you can fix with 2 M3x8 bolts and t-nuts. I use it to have a display for my Octoprint server with the Touch UI plugin.

The mounting holes are on the right side with 1cm distance so it mounts flush to a 20x20 extrusion on that side. You can mirror the print to have the holes on the left side.

For me the Nexus 7 has a snug fit so it doesn't woble around.

There is also a remix for mounting it to some heavy duty shelfs: https://www.printables.com/model/450875-gladiator-shelf-nexus-7-mount