The Snapchat app has been all the rage on iOS, so much that Facebook even tried to clone its functionality in their "Poke" app. Unfortunately for Facebook, which hasn't shown that much innovation lately, just copying a competitor's functionality is not enough to make it popular.
Snapchat has also launched on Android a few months agp, when they announced that their users have taken over 1 billion "snaps" of themselves, and they're now probably over the 2 billion mark. In December they've launched video messaging for its iOS app, but now they're going to add that to the Android version, too, although only for the private beta version right now.
As you probably already know, Snapchat is an app that takes private sharing very seriously. You can share photos and videos (now for the Android version, too) with friends, but then they can self-destruct, after a number of seconds or minutes that you set-up. This is to ensure that the photo or video you are sharing remains private, and is not going to be sent to others, or worse: made public.
Apparently there are a lot of people, especially teens who really like this functionality. This should be the same type of teens from a new generation that don't like Facebook, and prefer something a lot more private, which makes me wonder if new generations are going to care a lot more about privacy than the "Facebook generation". I think that can only be a good thing, as companies and governments, too, are now abusing people's data that they give to these sort of sites. So it makes sense that in the future we might need people and services that takes privacy a lot more seriously.
Snapchat introduced the video capability for its private beta version of the Android app, but I find it pretty strange that they didn't even let people download the private beta app for even a day, as it seems their download link has already expired. But if it's indeed beta, we're probably weeks away from a launch, so you shouldn't have to wait much more for it.