Decimal and Thousands Separators
The character used for decimal and thousands separator is related to the language (and language variant) and not the currency.
Some languages, like English, use the dot as the decimal separator while others, like French, use the comma.
Consequently, your customers will see it in one way or the other depending on their browser locale (language and language variant, like 'Canadian English' or 'Mexican Spanish').
For example, in Canada, you will see the prices formatted with a decimal dot on the English-speaking provinces and you will see a comma on the French-speaking provinces:
Currency Converter+ detects your customers' browser language and format the prices correctly according to their language. Some customers will see the currency symbol on the left-hand side and others on the right-hand side and with the right decimal and thousands separator.
This is also visually explained in our promo video at https://youtu.be/MT23mSWaTxc?t=52s