This is so cool! Coincidentally, I'm currently building something in a similar vein that pushes system metrics out to an Android app so an old phone or tablet can be used as a case screen. The app has widget plugins that expose a repo of metrics received and a GL surface, that can then be used to display fancy visualisations.

Check it out here: https://github.com/xfoa/humours. It's not finished yet, but the basic functionality works. It just has one widget at the moment that draws a spinning cube with temps, etc.