I have just added a new flowcard, once it turns out to work as expected, it will also become available as a BLL expression method.
Format [[number]] as decimal/currency/percent/unit card.
This card has dynamic fields.
You first pick if you want to format it as a decimal, currency, percentage or unit.
Then other options becaume available in the 2 option-dropdown-arguments:
Here an example of Currency, Dollar, with fullname, in Dutch:
By default, the locale configured in the BLL app settings will be used, but you can optionally enter another locale in the flowcard.
Check it out now in test: