Alright, so, one of the pieces of feedback I got was to add haptic feedback to the device. I threw a vibration motor onto the device and saw what it did.

The results were a little underwhelming. Yes, it was very simple to add, and yes, i can get a bigger one, but it was hard to feel the vibration while I was holding the device. Mounting also seemed to be very important to transfer the vibration through the case, which makes sense. You want the whole device to rattle, not just the motor. 

It was a pretty simple thing to add, and it should make it easier to determine when you are tagged. The only other thing I thought of adding was to invert the colors on the OLED display to indicate that you have been tagged. I think that combined with the vibration and sound should make it clear. Initial tests showed people didn't notice when they were getting tagged. Or, at least, wanted more feedback when they were. 

Also, the wires on this motor are tiny. It's fine, I can work with them, but stripping small wires is annoying. I cut through the whole wire twice. I guess I need to practice more with small wire.