This was a website often used by maths teachers as a lifesaver for them for setting homework. However, from the students' point of view it was the bane of their existence as each time there are different questions so you can't copy off someone.
You used to be able to just type in the link at the top of the page that would give you 100% but this no longer works to many students' dismay. A good excuse for not doing the homework is just “oh I must have forgotten to press the checkout button” as your work doesn't save unless you have pressed this.