It feels very much like "insiders solving very specific problems for other insiders" ... maybe insider isn't the right word, but my sense is they were born from frustrations with changes in the way Twitter handled the ecosystem ... i.e. 3rd party clients. So they said ok, we're going to build our own system that isn't trying going to restrict 3rd party clients.
So I (think) I get what they are on the periphery, but I still don't get the core product.
I'm sure it's good though - or at least good in spirit. Would love to hear more.
Can someone do an 'explain app.net to me like i'm 5 and have never used the internet'...?