Personal finance app with real bank synchronisation — because manual entry is where good intentions go to die.
Anna tracked her expenses manually in Notes. She'd forget transactions, categorise incorrectly, and end up with a monthly summary that bore no resemblance to reality. Existing apps either required manual input or connected to UK banks only — useless in Spain.
She needed: automatic bank sync across Spanish and European banks, smart categorisation, budget alerts, and a weekly digest. In Spanish.
Plaid Integration
OAuth bank connection flow, transaction sync, data model
Core UI
Account overview, transaction list with auto-categorisation, budget rings
Analytics + Launch
Spending charts, weekly digest notifications, App Store submission
Plaid in the EU
Plaid's European coverage required a separate OAuth flow for PSD2-compliant banks. Built a custom token refresh manager to handle 90-day re-authentication cycles transparently.
Smart categorisation without ML
Used Plaid's merchant data + a curated lookup table of 1,200 merchant patterns. Categorisation accuracy: 91% without any on-device ML overhead.
Privacy architecture
Bank credentials never touch our servers. Plaid tokens stored in the iOS Keychain. All sync happens device → Plaid → CoreData. Zero plaintext financial data stored externally.
Downloads in first month
Auto-categorisation accuracy
Rating, 89 reviews
"I finally know where my money actually goes. And it happened without me doing anything — the app just figured it out. Worth every cent."