Duolingo doesn't work at all for me, I learn to solve their mini-games without actually learning the language, even after spending a lot of time on it. For some reasons my brain get the information, as proven by the fact that I pass the exercises, but I'm not able to use it in a non-gamified context. Seems to be an issue with the method itself.

Anki + an actual textbook + grammar reference is not fancy and requires a lot of time and commitment but I haven't found anything else that works.