You found the authors' screen names and some other things they've made.
That's not finding who they are. No one has signed their names, like their real names, to this. Who are they? Intelligence agents? For which country? There's no way to know.
At least one of the authors is Russian. They were giving away Helium stickers to “anyone who is in Moscow”, and not many non-Russians are traveling there nowadays.
https://github.com/imputnet
I now found who exactly manages this (and it turns out colbalt, too! awesome downloader)
https://github.com/wukko https://github.com/dumbmoron