Splitwise

Splitwise handles the math on shared expenses automatically: photograph a receipt, pick who was included, and the app calculates each person's share instantly. It works offline and syncs when you reconnect, tracks recurring bills like rent, and can even figure out the optimal payment sequence to settle everyone's debts with minimum transactions. Completely free with optional premium features like automatic credit card syncing.

Best for groups of three or more where bills overlap in complex ways. Transforms group finances from guesswork and awkward conversations into clear, itemized records. Unlike Venmo, it's built specifically for tracking ongoing shared costs rather than one-off transfers, making it indispensable for student housing.