Vine (owned by Twitter) is a hugely popular app in the teen and college-kid world. Users produce looping, six-second videos that range from strangely goofy to pensively artistic.
I check out Vine periodically just to maintain an understanding of the service, and have found it...well, mostly annoying, to be honest. Even the funniest zingers are not remotely entertaining once they've auto-replayed a time or two, and many times users are solely striving to be recognized as funny or clever by their peers.
And we all know that teenagers, God bless their little half-baked selves, they tend to have a very strange sense of humor.
The thing about Vine, though, is that I do see hugely redemptive qualities within this app. Because of the ease in time-lapsing videos, kids could use Vine to record various parts of science experiments and their findings...a much more authentic use of the traditional science report that would command the type of communicative precision required in a global society. Kids could also Vine their reflections on a book they've read, or even use Vine to design or frame up a short story they're writing in an ELA class. They could use Vine to create tutorials for completing math problems (great for teachers implementing the flipped instruction strategy) or for demonstrating how to properly shade a 3-D picture in art class. My favorite aspect of this app is the raw creativity kids can show off when crafting a well-executed Vine.
Because Vine's Terms of Service are pretty open, nudity and sexual content (just as with Instagram or any other microblogging platform) is accessible to anyone who knows where to find it. From what I gather, Vine has taken strides to prevent the inclusion of pornography in any collections (removal/banning of certain hashtags) but anyone considering classroom use for this has to go into it with the understanding that though it's entirely possible to avoid explicit material, it's also still there for anyone who goes looking for it. I wouldn't recommend it for elementary or middle schoolers at this point (not until a tighter community or circle of security can be drawn around student users), but can see it being really useful for some high school groups. Teacher savvy is key to effective integration of this app!
More resources on Vine:
Vine: What Parents Need to Know