TL;DR:  Get a lifetime subscription to  Qlango Language Learning,  with 71 languages included, for $49 (reg. $239). Learning a new language is no small feat, but this app is making it a little bit easier. Qlango isn't trying to guilt-trip you into a 365-day streak – it's more like a video game that happens to  teach you Croatian . Or Korean. Or Esperanto, if you're that kind of guy. And, right now, lifetime access is available for $49 (MSRP $239). Science-backed language learning techniques Here's what actually makes Qlango different from the sea of language apps out there: spaced repetition. It's a  scientifically backed technique  where the app reintroduces vocabulary at spaced intervals, right before you'd normally forget it. Think of it as hitting "save" on words your brain keeps trying to delete. You'll work through 6,679 of the most commonly used words in each language, with example sentences built for real-world conversation.…