Yípo
Offline Ajo & Esusu Mobile Record Keeper
A high-performance, offline-first Android application engineered for Nigerian Ajo, Esusu, and Adashe rotating savings organizers. Functions strictly as a secure digital ledger (never touches money) to automate contribution rounds, payout schedules, WhatsApp receipts, and member reliability scoring.
Android Native Interface & Offline State
What I Built
Sole Mobile Engineer & UI/UX Designer. Built 100% offline-first Android architecture on React Native and Expo (SDK 58): transactional SQLite ledger with ACID guarantees and migration schemas, custom Shopify Skia visual rotating turn ring, native Android biometric lock (Fingerprint/Face ID), Android Share Intent receiver for payment receipts, direct WhatsApp receipt deep-links, embedded-font A4 PDF export, and universal ARM32/ARM64 production compilation via EAS Build.
The Hardest Part
Designing the transactional multi-turn rotating savings ledger in local SQLite with instant optimistic updates, reversible 4-second undo states, and dynamic Skia canvas ring layout calculating polar coordinates across arbitrary group sizes at 60fps.
Screen Gallery
Interactive Skia ring: active payout collector spotlight, pot progress, and member payment states
One-tap payment recording drawer: installment balances, instant undo toast, and payment note attachment
Direct WhatsApp automation: deep-linked payment receipts and scheduled member reminders