Splitwise

Splitwise is a free tool for tracking shared bills and expenses. Friends, housemates, couples and travel groups record who paid for what, and the app keeps running balances so everyone can see who owes whom and settle up. It is available on the web, iPhone and Android.

Expenses can be split equally, unequally, by percentage or by shares, and groups can add recurring expenses, simplify debts and see spending totals. Users can categorize and search expenses, work offline with cloud sync, and record cash or online payments when settling up. The optional PRO tier adds receipt scanning, itemization, charts and graphs, currency conversion, transaction import and an ad-free experience.

Splitwise is a hosted consumer service and cannot be self-hosted. The core features are free to use, and PRO is an optional paid upgrade.