CaliRider,
I think your homies are working in the wrong direction..
Rather than deal with design/manufacturing pain, they should write software for iphone (I bet it has same of better gyro chips) and bundle it with rubberized sealed case that mounts on to the board (maybe using the handle screw holes)... Either way, they'll need to do the software part, so it's a huge shortcut.
They can probably find decent market for it, selling the bundle for $50-60
There is still the same issue that started this and many other threads - calibration for each phone version will be different.. so when you post 15m jump on iphone 8, you friends with iphone7 will be skeptical and so are people with woos, xensrs, etc..