Let’s say you’ve got a group vacation going on — a cross-country road trip, or a weekend trip to Vegas, perhaps. Figuring out who owes what for gas, hotel rooms, dinners, groceries, and other payments can be a spreadsheet nightmare. Luckily, the app Splittr ($2 on iOS; there’s a similar, unrelated free app by the same name on Windows Phone) makes this super easy. Simply create the trip or event, then add individual expenses for that activity. From there, you can add the parties involved in that activity and how much each person contributed thus far.