Currency Converter Offline
170+ currencies, signal or not.
Currency Converter Offline keeps rates locally and refreshes them hourly whenever a connection is available, so conversion keeps working when the network drops and sync picks itself back up when it returns. More than 170 currencies, historical charts, and 20 interface languages.
- Year
- 2024
- Platforms
- Android
- Publisher
- Codeur d'Ivoire
- Technologies
- React NativeExpoTypeScriptREST
- 170+
- Currencies
- 20
- Languages
- 1 h
- Refresh cycle
Case study
The problem
A converter that calls an API on every conversion breaks at exactly the moment you need it: travelling, in weak coverage, or out of prepaid data.
What I built
An offline-first architecture: rates are stored on the device and are the source of truth for the interface, the hourly refresh runs in the background when the network allows, and a failed sync is retried later instead of blocking the UI.
The result
Instant conversion at all times, data use reduced to short refreshes, and an interface available in 20 languages.
Features
- More than 170 currencies supported
- Exchange rates refreshed every hour
- Offline-first operation with deferred synchronisation
- Historical charts showing how rates have moved
- Interface available in 20 languages
- Instant conversion from locally stored data, with no network wait