great question really
I like the littleBits website, especially this community forum.
I researched Learning Management apps, to keep in contact with kids who came to my workshops,
Unfortunately there is this great FUD over letting kids under 13 use email... anyway, the best I found so far is Edmodo. That allows for kids to follow a teacher's (or facilitator's) post and also monitoring by parents.
I'm really looking for a tool that allows me - as a "teacher" - to do a reverse classroom.
I went a bit off-topic from your original question perhaps... hope it still answers it.
ALso try out the iOS app and comment on other's projects.