Formerly known as "Rapid Currency Converter".
This currency converter has everything you'd expect from a great currency converter. Latest exchange rates are stored locally for offline usage, there are lots of colorful themes and it also has a built in calculator for quick math. You can combine 3 out of 19 different sources of exchange rates including Yahoo finance, European central bank, Bank of England, Brazil central bank, Central bank of Russia, some exotic countries like Thailand or Vietnam and many more (complete list below). And the best thing is that you see instant conversion to all of the foreign currencies at once, no need to select just two of them.It is also translated into 20 different languages, so it's really a world-wide ready app.
App was promoted in printed version of Guardian.co.uk magazine on 7th of January 2017 (Android version): Swift (Rapid) Currency Converter in Guardian.co.uk. That has to mean something, right?
List of exchange rates sources:
European Central Bank, Bank of England, Yahoo finance, Brazil Central Bank, Central Bank of Russia, Bank of Canada, Reserve bank of Australia, Bank of Thailand, National Bank of Ukraine, Bank of Israel, National bank of Moldova, National bank of Denmark, National bank of Romania, Bank of Iceland, National bank of Kyrgyz Republic, Czech national bank, Vietcom bank, Swiss national bank, Bank Pekao Poland