Even though I made an app that helped me along the way to learn words, I don't believe in a single app/book/approach for learning a language. You need to expose yourself to A LOT of different language materials.
I was learning for about 2h a day, 6 times a week. I would read articles, books, websites in Spanish. I would watch YouTube videos [1]. I would read news, initially for beginners [2] and later regular [3]. And most importantly, I would have 4-5h a week itakly conversations.
After 6 months I understood quite a lot, but couldn't speak almost at all. Then magic happens and 6 months later, I was having a normal conversation (though still with some errors) about any range of topics: politics, global warming, travel, engineering etc.
I believe the key for me was to read a lot of books which were interesting to me. For example I read Bill Gate's book "How To Avoid A Climate Disaster" in Spanish, as well as about ~8 others in the first 12 months.
[1] https://www.youtube.com/c/DreamingSpanish
[2] www.newsinslowspanish.com