Does everyone need an account to play?
No. You can register a player as a guest. They sit at the table, buy in, get eliminated and get a finishing place and points in the tournament like anyone else — without downloading a thing.
It is the usual way to get a club going: run a couple of tournaments with guests, and let people make an account when they actually want to follow along themselves.
What do guests miss out on?
Everything about following along on their own: signing up in the app, notifications, their own stats over time, and watching the tournament live as it runs.
They are not ranked over time either: guests do not appear on the club scoreboard, in league standings or in the member list. They stay in the results of every tournament they played, and they count towards the field size, so everyone else’s points still come out right.
Can a guest become a full member later?
They can create an account and join the club normally. Old guest results do not automatically move across to the new account — they stay as their own rows in the history.
If that matters to you, it is worth asking people to create accounts early rather than late.
Why do I suddenly have two accounts?
Almost always because you signed in with a different method from the one you created the account with — typically Facebook, which often carries a different email address from the one you signed up with.
The fix is to connect the sign-in methods to the same account instead. See Sign-in methods.