The Calrec Summa broadcast audio console had two displays. Both were backed by Android in terms of the graphical user interface and interaction. One screen controlled everything while the other presented the audio levels.
I used my expertise with OpenGL to create a hardware optimised GUI system. This was before Jelly Bean came along.
Funily enough, the biggest slow down was the alpha blending which I minimized as much as possible. Looking back, the next step would be to optimize the geometry around the alpha areas.