It's a good extension overall but I'd be nice to be able to choose if you want to use a comma or a period for decimals, and also how many numbers after the comma you want. Coming from a country that uses commas for decimals and periods for thousands, and having the extension do 3 numbers after the period makes it a bit confusing to read.

Please make it work on Android (add preferences or settings and make sure the extension reacts to JavaScript changes on the page, not just page reloads).

Add R$BRL

Very nice but hide ur API keys and ask the end user to register an account on unirateapi instead of using your own API keys.