When you first open up the application, you'll see all world currency rates against one currency. You could change this base currency on the top right base button. You could easily go to the detail of the selected currency and have the detailed data with a line chart in the intervals of last one week, one month, one year and five years.
While developing this project, I focused on using all the benefits of Kotlin and applying it by following the software architectural pattern: MVVM. I tried to decrease the dependencies between my classes by applying Kotlin-Koin and for asynchronous programming I used Kotlin-Coroutines. After all, dealing with all this data, I used one of the android architecture component "LiveData" to make my application lifecycle aware.