First, I'd like to thank Pololu for creating Wixel! It's a great solution for small, low-power wireless projects.
I'm working on a quiz button app for Wixel. The software is intended for a small number of participants (at most 8 people or teams) to be able to participate in a jeopardy-style. I started out trying a peer-to-peer architecture, but never came up with a simple solution to break ties with simultaneous button presses. I changed to a client-server architecture, where there's a "master" button that controls the state of the whole network. The code is in pretty good shape, but I've only tested with four Wixels sitting close to each other on my desk. I don't plan to do anything complicated like scorekeeping or timekeeping with this code, just determining who pushed their button first.
Here's my github repo:
I'm still working on figuring out my enclosures, but I'm going to try to set something up using big buttons that participants can smack.