How does a group know everyone has added their expenses?

Before a group settles up, everyone should have added what they paid for. Open the group: under Balances, a row says how many of the people in it with Evensies have added everything. Tap I'm done once you have.

Tap the row to see who is still adding and who has added everything, and to turn I've added all mine on or off. If you add or change an expense after saying you're done, Evensies takes your mark off, so the group never settles on numbers that have moved. A deletion leaves it on.

When the last person says they're done, everyone else in the group gets a notification that it's ready to settle up. Once anyone has said they're done, Settle up also names whoever is still adding.

An owner or admin of the group can tap Ask everyone to finish. Everyone still adding gets one notification asking them to add the rest of their expenses, if they have Group activity on, and Evensies says how many it reached. It can be sent once a day in each group.

Names added by hand, for people who aren't on Evensies, aren't counted: they have no app to say it with. Someone added by hand can still have their expenses added by anyone in the group.