Our code is built on top of their gem. We focused on the rebilling logic, which replicates some of their own vault / rebilling code, which most people here would say was a waste of time / money. (Probably was?)

When it comes to billing stuff, though, I really want to know what's going on behind the scenes ... hence ... rolling our own.

As we work out the bugs, I'll try to get a gem together. Would love to have people dig into it and make it better.