How it works on a trip
Create a group for the trip and add your travel buddies. Log the flights, the apartment, groceries and dinners as you go; each expense can be split equally, by exact amounts, by percentages or by shares, so the friend who skipped the boat tour does not pay for it.
When the trip ends, the settlement plan lists who pays whom. Record the payments one by one or settle everyone at once, and keep the plan as a PDF.