Awesome! Yes, iTalki is a good app but I haven’t implemented it as much as I should, unfortunately.
I’ve heard good things about Speakly but I haven’t tried it out yet. I need to download it, now that you mention it.
I disagree with your last point of sticking to one good resource. The issue there is most people become bored with using the same tool. That’s why it’s good to learn a few lessons on an app, then watch a movie or show or read an article in the target language. Or you could go shopping or to a restaurant and try out the language there. It’s best to try different methods at once so you can actually see the language used in real world scenarios.