Mobile · Algorithms · Product
splitB — iOS Bill-Splitting App
SwiftUI group-expense app with a network-flow settlement optimiser, released on the App Store
Role
Sole developer — product design, app architecture, persistence and sync, and App Store release.
When
Personal project · released
Tech
- SwiftUI
- Core Data
- Firebase Firestore
- Swift
Designed, built and released independently: group creation, expense and record management, member balances, Core Data local persistence, and Firebase Firestore sync with invite codes and real-time group updates.
Numbers that are real
Apple App Store
Released on
10+
Real users
What I did
- Implemented a network-flow-based settlement algorithm that restructures inter-member debt into a lower-cost repayment path instead of preserving the original pairwise debts.
- Built both persistence layers: Core Data for local data and Firebase Firestore for shared groups, with invite codes and real-time group updates.
- Shipped the app to a working, real-user state rather than a UI prototype, and released it on the Apple App Store.
- Owned the full product loop: data model, balance calculation, sync edge cases and release.
Honest limitations
- The settlement optimiser is implemented, but settlement quality was not benchmarked — no reduction in transfer count or total transferred amount is claimed.
- The exact cost function (and whether the optimiser explicitly minimises transfer count) is not documented outside the code yet.
- Next steps: quantify settlement quality and publish the repository.