Perch is an iOS app, though there isn't an iPad-specific version yet. The idea is you take an iOS device like an iPhone, attach it to your wall, and start up the Perch app. It just hangs out there, waiting for someone to come along.
Perch is always on. It uses facial recognition to identify a person who steps up to it, gives you a countdown, then automatically starts to record. You share your message ("I finally reached Level 60 in World of Warcraft!") and it sends it along to the remote users in your Perch family. Those people can check the message at their leisure and then record and send replies.
Due to the nature of Perch, it works best with an old device you're not using as a day-to-day phone or tablet anymore. It requires iOS 6, so the device can't be too old. Perch is currently free, but you'll have to sort out your own wall-mount.
Despite the obvious surveillance potential, Perch is being positioned as a solution for families. It's a pretty painless way to pass video messages around, especially for parents who are on the road a lot, but don't want to miss out on what their kids are up to.
Speaking of surveillance, there's a motion detection feature that can be turned on, should you want to keep tabs on your house or catch the dog in the act of sneaking food off the counter.
(Via Opportunity Notes)