Currency Conversion App Following Modern Best Practices

This app allows users to view a given amount in a selected currency, converted into other currencies using real-time exchange rates.

Check out the app's demo video:
App Video Link

Build On

• Kotlin version: 2.0
• Android Studio: Ladybug
• Runtime version: 17.0.11+1-b1312.2 aarch64 (JCEF 122.1.9)
• VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.

Functional Requirements

• Fetches exchange rates data from the free version of an exchange rates service.
• Perform the conversions on the app side if exchange rates for the selected currency are unavailable through Open Exchange Rates.
• Supports offline mode, allowing the app to be used after the data is fetched and persisted locally.
• The app refreshes the required data no more frequently than once every 30 minutes to minimize bandwidth usage.

User Interactions

The app's UI is built using Jetpack Compose and provides the following features:

• Currency Amount Input: The user can enter the amount they want to convert.
• Currency Selection: The user can select a currency from a list provided by Open Exchange Rates.
• Converted Amount Display: After selection, the app displays the desired amount converted into various currencies.

Environment Configuration

The app uses the Base URL and OpenExchange App ID from the env.secrets.json file, located in the app directory, to make API requests.

Testing

• Unit Tests: The project contains unit tests that ensure the correct operation of the app.

Architecture

The app adopts the MVVM architecture, following the principles of The Clean Architecture and S.O.L.I.D to maintain a scalable, maintainable, and testable codebase.

Libraries and Tools Used

The app uses the following libraries:

• Kotlin Flow
• Coroutines
• ViewModel
• Jetpack Compose
• Dagger Hilt
• Retrofit
• Room
• JUnit
• Turbine
• Espresso

Note: To run the project, add your Open Exchange app_id to env.secret.json.