Station managers and cashiers, on event day without internet

1. Keep the app open and the nearby devices permission granted: the event phones find each other on their own and share what's been handed out every few seconds, with no network or router.
2. At the top of the screen you see how many phones you're in touch with and how long since you heard from each station that accepts the same vouchers.
3. If it turns yellow, you've lost contact: move closer to the other station or ask someone to walk between the two with their phone. Meanwhile, a voucher the other station already handed out could go through here.
4. If a voucher says “already handed out”, check where and when: it learned that from another phone. Don't hand over again.
5. When someone finds signal, it uploads everyone's data: not everyone needs to connect.

It only works with the Android app. The web page needs internet to know what the others handed out.