UPDATE:
I added more functions:

1) JavaScript price update without reloading the page. Reloading the entire page was ruining the users experience. The price is now highlighting for each price update.

2) Copy to clipboard by clicking the price + notification.

3) I added all the currencies possible:
Examples:
https://1btc.to/?currency=usd
https://1btc.to/?currency=eur
https://1btc.to/?currency=gbp
https://1btc.to/?currency=aud
https://1btc.to/?currency=cad
https://1btc.to/?currency=inr
https://1btc.to/?currency=rub
https://1btc.to/?currency=cny

... and so on. Only 4 currencies are not available.

4) Responsive design.

More than 500-600 users per month seems to use this checker so because of that I said to make it better! It was a BS before, now is better