YARC - Yet Another Rate converter

YARC allows you to select the rate converter service you want.

For now, the app supports 2 services (more to come!) :
- Exchange Rate Api: free service, usable without any configuration, but with a limited number of currencies
- Fixer IO: sign up required on their website (free or paid account), with almost all official currencies

YARC has been designed to easily add new rate converter services. Cypto-currencies support will arrive.
