title: Need API for currency converting
body: <p>Please advice API for currency converting which returns JSON or small size html. 
  I use <a href="http://www.google.com/finance/converter?a=1&amp;from=RUB&amp;to=USD" rel="noreferrer">http://www.google.com/finance/converter?a=1&amp;from=RUB&amp;to=USD</a> that returns HTML of 11 kb. 
  I use it in my iOS app.</p>
  
  <p>Thanks in advance! </p>