I expect I'll be drawing my own shield in Eagle and having a batch of boards done by iTead. I've had excellent luck & results so far with both.
I haven't done the first bit of Android programming yet, I don't even own the tablet. For now, I'm guessing that putting a bluetooth module on my board will be the route of least resistance. "The plan" for the moment is to build a control panel with three 8x2 lcds (temp and volume for each container) and a 20x4 for everything else (machine state, time remaining for each step, etc). That will be easy enough, and I can teach myself Android as slowly as I want at that point.
What you've done here, though, seems years ahead of what I envision even my finished product to be.