The Ruiz Brothers made this real nice case for the iPad Pro 11″. I have been using one on mine since I got it. But it was missing the cutouts for speakers and microphones. I was able to find the Apple Accessory Design Guidelines and get the dimensions and placement of these items.
I built a bluetooth camera slider following this Adafruit tutorial – https://learn.adafruit.com/bluetooth-motorized-camera-slider/overview. But I wanted to improve the design on the bearing mount and the camera platform. This video shows the changes I made in Fusion 360.
Thingiverse link for upgraded parts – http://www.thingiverse.com/thing:1496753