Component is triggered by a Cron Job.
It looks for recent uncompleted orders, that are older than X days (and that doesn't have a younger sister order from same customer, or that has not allready be reminded).
It then, sends an friendly email to the customer reminding him the order, with a link tot he order details and optionaly a coupon code.

The email is sent in the customer language (if set).
You can try, ordering this extension, checking out and not confirming payment. You'll be kindly reminded in the next day