01CONTEXT
Product / Mobile
2026 · ACTIVE DEVELOPMENT
PROJECT / 03
RECURRING PAYMENTS · MOBILE PRODUCT
Subscription Tracker
A recurring-payment app with persistent billing state, payment tracking and synchronized reminders.
Drift persistence · synchronized reminders
02STACK
- Flutter
- Dart
- Drift
03STATUS
Active development · Android-first recurring-payment application
Case study / 2026
01PRODUCT PROBLEM
Recurring payments need more than a simple list.
The application is designed around recurring financial commitments such as subscriptions and regular payments. The goal is to make billing state, amount, currency, payment timing and reminder behavior explicit instead of treating every recurring charge as an isolated list item.
- Recurring payments
- Billing state
- Product design
- Android-first
02DOMAIN MODEL
Payment rules are handled as controlled state.
The application uses explicit add and update flows for recurring payments rather than allowing arbitrary state changes. Optional values such as payment nicknames are normalized, while currency input is validated before persistence so invalid changes do not enter the stored payment state.
- Application layer
- Validation
- State transitions
- Money rules
03PERSISTENCE
Local persistence is kept behind repository contracts.
Recurring-payment data is persisted through a Drift-backed repository layer. Repository behavior and round-trip updates are tested so edits, cleared optional values and stored payment state remain predictable across application and persistence boundaries.
- Drift
- Repository pattern
- Persistence
- Contract testing
04NOTIFICATIONS
Payment updates and reminders stay synchronized.
The recurring-payment workflow also coordinates notification behavior. Valid payment changes can propagate to persistence and reminder scheduling, while rejected changes are stopped before they create additional repository or notification side effects.
- Notifications
- Scheduling
- Consistency
- Edge-case handling
CASE EVIDENCE
Project evidence
DASHBOARD
Payment overview and monthly summary
The dashboard highlights the next payment, quick actions and grouped monthly totals across tracked subscriptions.
SUBSCRIPTIONS
Active subscription list
The subscriptions screen presents active services such as ChatGPT, Disney+ and Netflix in a clear list view.
RECURRING PAYMENT
Add payment flow
The recurring payment form captures title, amount, cycle and currency in a focused creation flow.
SUBSCRIPTION DETAIL
Detailed billing view
The detail screen shows billing amount, cycle, category and the core attributes of an individual subscription.