Decide whether the bride pays
Many groups cover the bride. Her share is spread across everyone else, so each person pays a little more. Say it in the first group message, before anyone books flights, so nobody is surprised later.
If the group is large, covering the bride adds very little per person. If it's four or five people, check the number in the calculator first and agree on it together.
Collect before the trip, not after
Whoever booked the house is out of pocket from the moment she pays. Ask for shares as soon as the booking is confirmed, while the plan is fresh, instead of chasing people after the weekend.
In GroupTab, the person who paid for the house taps “Ask everyone for their share now” on that expense. Each person sees what they owe for it, with a button to pay.
Handle the odd cents fairly
A total rarely divides evenly. The calculator gives the leftover cents to the first people on the list, one cent each, so the shares always add up to the exact total. GroupTab uses the same rule inside a tab, so the numbers match.
Keep the rest of the weekend on the same tab
Dinners, decorations, the boat, the rideshares: add them as they happen and let the tab work out who owes whom at the end. It boils everything down to a short list of payments, so nobody sends money in circles.
GroupTab keeps everyone's Venmo and Cash App in the tab, so paying is one tap with the amount already filled in, and both sides confirm when it arrives.