it just taught you words/phrases without really giving you much explanation behind what you were learning so it was hard to try to put them into practise.
Bingo. There's no pedagogical foundation to Duolingo. It's basically an electronic phrasebook. And I've tried the computer version; it's got more bells and whistles, but structurally isn't any better than the app.
Programmes like this have been around for decades -- anyone remember Rosetta Stone? They give people the illusion of learning because they offer what looks like concrete progress. Here are a bunch of words and phrases you didn't know when you started, but now you know them! See, you're learning! But I have been a language teacher for over 15 years and have studied language acquisition, and I promise you that this is not substantive and not sufficient to really get to grips with a language, even at a beginner level.
I'm not saying that there's any harm in using Duolingo or any of the others. Any language study is better than none at all. Just please don't buy into the hype. It's a free app, it's not going to magically confer upon you something that has always taken years of dedicated study.