Can I attach a buggyboard to this stroller?
In theory, yes, you can - some of the universal ones, e.g. Lascal Buggy Board or Bumprider should fit and be usable. However, the stroller is VERY small, it is from the group of ultra-compacts (more about those here) meant fo occasional use and traveling, meaning NOT a sturdy, robust frame. Such strollers are much more prone to loosening up, getting damaged etc. by overstraining them, and that is why I perosnally WOULDN'T recommend using a sibling skate in the back.