Sounds like more of an acquihire than they actually wanted the app, based both on how much they put into it in resources after purchase, and how much they sold it back for.
The only thing that made it an acquisition more than an acquihire is that we had products that were generating revenue, so they couldn't just give us jobs and regular options packages.
Our employees started at GitHub with regular options packages, but Steve and I got a little more because we were the owners.