If you have a lot of intrinsic motivation, Anki will probably make you learn the languages the fastest (or maybe you pick one of the two, idk how Norwegian Bokmรฅl and Nynosk interact)
If not, some gamified thing like Duolingo keeps a lot of people engaged for ages apparently. Keep in mind that even their scientific papers are using engagement as the metric by which they score different spaced repetition parameters, not lesson retention. My grandma has been doing English for a year and I have yet to hear her speak two words, but she loves the characters and enjoys it a lot and that's the important thing for her ^^. If you've already got the book for the in-depth part, this could be a way to supplement by building a habit of daily learning
I'd guess that most other software is somewhere in between, at least on learning efficiency (like listening to audio books as someone else suggested: ok that's great and engaging, once you have a solid foundation at least, but it's only listening comprehension and you already need to know a lot so the further learning is somewhat limited)