Walk-up football. Arrival order buys the right to play, and a published calculation draws the teams.
If you run a group, sign in to open a session, record who has arrived, and draw the teams.
Your group will have its own address, like
/your-group/sign-in, which is worth bookmarking.
You do not need an account and there is nothing to sign up for. Your coordinator gives you a short code once, you type it into your group's page on your phone, and that phone is yours from then on.
Every session has a record showing who arrived and when, how the teams were drawn, and the exact sum used. Ask your coordinator for the link.