English and Apps

I love learning about other languages and cultures; they're positively fascinating. It is entirely possible that I should have chosen to major in Anthropology instead of English Literature, but I digress.

Due to this mild obsession, a friend recently pointed out a free website called Duolingo which, as the name suggests, helps you learn a second language.  I chose German. After two days of using the service during study breaks and bouts of boredom I have acquired several useful phrases such as "Die Frau trinken das Wasser" (The woman drinks the water) and "Der Mann isst eine Fischsandwich"(The man is eating a fish sandwich).

Linguistic dabblings aside, this has been a very productive evening. I came up with what could either be a brilliant idea, or the dullest suggestion anyone has ever heard. What if we, as teachers, could develop phone or computer apps for our vocabulary lessons?

All of my students (6th grade) have cell phones, the majority of which are smart phones. If this is true for the majority of the student population, why couldn't we come up with a more tech-savvy method to help students expand their vocabulary?

This Duolingo app introduces new vocabulary slowly, perhaps seven words per mini-unit. When using the app, you are asked to form sentences using the vocabulary, point out similarities, et cetera.
Wouldn't it be neat if teachers could plug in their own vocabulary words into an app? One that students could download onto their phones and use to review vocabulary or even as a homework assignment?

If such an app already exists, could someone kindly point me in its direction?

If it doesn't, well it looks like I found something to do over the summer break after all.