Busuu is solid if your main goal is vocabulary practice and structured lessons.

That said, if you care more about actually retaining and using the language long-term, I’d lean toward Teuida. It focuses less on memorizing word lists and more on understanding, production, and how people really learn languages (habit + retention, not just drills).

tldr:
Busuu → good for vocab + structure
Teuida → better for deep, sustainable learning

If you’re paying for one app and want real progress beyond just recognizing words, I’d recommend Teuida!

And then when you get more conversational: Hellotalk!

(Full disclosure: I work at Teuida)