Verbling pairs you up with someone who speaks the language you are learning and is learning the language you speak. The app times you and for the first 5 minutes you are supposed to speak one of the languages and for the next 5 minutes the other. At the moment, its language coverage seems to be limited to Spanish-English combinations, but you can select from a variety of languages.
An app like this certainly wasn't hard to see coming. Back in 2010, when Chatroulette first rolled onto the scene, I wrote:
[V]ery little would actually need to be done to make the model effective for language learning. First, you'd of course need to toss out all the pervs, etc. That sort of thing doesn't seem to be an issue at all on Livemocha or other online language learning sites, so it shouldn't be a big deal to do that.The chat partner filtering is clearly on the right track, but it wasn't apparent to me what safeguards they had in place to deal with the pervs, but I'd hope that the language-learning crowd would be a bit easier to corral into decency than the Chatroulette crowed.
The second thing is that you'd need to be able to filter your chat partners. At a minimum, you should be able to filter by target language so you can get someone who speaks the right language for you, but being able to filter by age, interests, etc., could also be useful for finding someone interesting to talk to.
I gave it a go in the evening Tokyo time and there weren't very many people on to chat in Spanish with. I eventually managed to speak with a science teacher from Spain after a few abortive attempts foiled by technical issues (namely, he couldn't understand what was being said on my end, although everything seemed fine as far as I could tell). Naturally it was the kind of small talk you'd expect, but it was a few minutes of using the target language (and, thankfully, it was all perv free).
The biggest thing that Verbling seems to lack at the moment is numbers. To accommodate all the various language combinations that there are out there, they'll need a critical mass of speakers of various languages that just doesn't seem to be there yet. That said, it's a great effort and I look forward to hopping on there from time to time to chat in some of the languages I don't get to use so often in Tokyo.