Amazon Fire 7" Wall Mount

This is a wall mount designed for an Amazon Fire 7" (the $50 version). I designed this for a project at work to mount outside conference rooms for scheduling and the mount is designed to mount onto the face of a recessed power receptacle (with USB power or a small 120v to USB adapter). I designed it with a relief hole for the USB cable to reach outside of the mount without interfering with the placement of the mount against the wall box faceplate. It is designed for right exit of the USB cable but can be flipped if necessary. I suppose this could also be mounted in portrait mode if necessary as well but the mounting holes may not line up depending on the wall box used. Inspiration for this mount was from http://www.thingiverse.com/thing:1067747 but this was designed from the ground up due to issues I had with that mount and since it was being attached to a recessed box and not just a wall. Any modifications or suggestions for improvement please let me know!