Moeda Rápida

About the project

Moeda Rápida is a currency converter for Android and iOS that uses exchange rates stored on the device. Users can continue converting amounts offline while seeing when the rates were last updated.

Problem

While traveling, an internet connection may be unavailable when someone needs to compare prices or check a purchase. Requiring a network request for every conversion makes an app less useful in those situations.

Solution

The app saves rates retrieved from its data source and uses the latest available rates when offline. The interface shows their update date so users can distinguish stored rates from recently retrieved data.

My role

I developed the architecture, exchange rate integration, local storage strategy and interface. I also managed publication on Google Play and the App Store.

Key features

• Conversion between multiple currencies
• Exchange rates stored on the device for offline use
• Last update date display
• Exchange rate lookup and history

Architecture and technical decisions

The app uses React Native, Expo and TypeScript. The exchange rate layer is separate from the interface, which reads local data. When a connection is available, that data is refreshed in the background.

This centralizes connectivity handling and gives screens a consistent lookup flow using the rates available on the device.

Outcome

Published on Google Play and the App Store, with ongoing development.

Technologies

React Native, Expo and TypeScript.