Normally yes, First of all I did this component to be use in store. (multiples stores) after that I did the integration with web shopping cart.
If you want I have a basic web interface (without Joomla), this interface is useful for the multiple store, employee can check if gift card is paid and they can use this same interface to mark them used. (there no balance amount, only full use).
It's very basic and free if you need it, you just need to protect the file with a htaccess (password) like that no need to enter the Joomla admin to verify if the card is valid.
If you want to use the gift card in two different web site, this is a little more complicated, but pretty easy to do too.
Let me know