CONVERTER app can be used to calculate currency rate.
Select the home currency by taping the scale icon. Select the target currency by taping the down-arrow icon. The exchange rate is fetched from the internet. Enter the home currency value or the target currency value. The other value is calculated automatically.
Tap the €-icon to show the currency exchange rate and the target currency name. These can be changed manually.
On the currency selection page a long tap on the a currency button shows the currency name and country. The fetched currency exchange rate is saved when moved back to the main page.
The app is free to use and does not show any adds.