Just finished my own DIY frame and tablet mount for home control. It’s making use of tasker, sharptools and kwgt to display key information on the home page. For layout, I am using Total launcher with flattered theme. In addition, TinyCam Pro for viewing my IP cameras, News widget, Google Keep widget for notes, and Fotoo app for screensaver.
For power supply, I am using existing 24V power supply that was available for my old wired home alarm system.
Nice job. Very much like the dimensional nature of the mount and how it goes with the room. I noticed you are using a traditional USB charging cable. Feel free to check out www.makesbymike.com for slim hidden charging cables for tablets. Hiding the charging cable would allow the mount to be the sole focal point.