As Jason said, every parent who codes has imagined doing something like Kidpost, and it's great that someone as sharp and sensitive as Khoi Vinh is doing it.
Kidpost is promising to solve the problem of sending the latest kid photos and updates and posts and such to all the right family members and friends. And it's doing it in the simplest of ways: by rolling up the things you tag on your various social media and web sites--Twitter, Facebook, Instagram, whatever and whatever--and dropping it into one weekly email. Which you send to whomever you choose.
Parents control what goes out and who gets it, and no one needs to download anything, or sign up for this or that additional service, or subscribe to whatever. You set it, tag stuff as you go, and it's done. It sounds awesome.