Payback
I already paid.
Tank = confirmed / owed. Nags after the deadline.
Shared ledger · not a bank
Stop losing $23 in the group chat.
One friend covers dinner. The rest ghost the Venmo. Collectuus makes the tab a tank the whole group can see — then you settle how you actually pay.
Pot-first
Don’t buy yet.
100% sent → safe to pay the vendor. Still no escrow.