Resources for things like vocabulary building and such will vary by your target language. However, the "memorization techniques" of most language apps really b

Resources for things like vocabulary building and such will vary by your target language. However, the "memorization techniques" of most language apps really boil down to "spaced repetition" (SRS) of some form, which is basically doing reps, and having the space between reps increase over time as you remember them better. Anki and Mochi are two spaced repetition systems (which will require you to create or find your own flashcards, but will take care of spacing out when to review them), and if you google for spaced repetition software targeting your target language, you'll probably find other alternatives too. I personally find Anki to be a joy of a piece of software, and after using it for 5 years I have no intention of stopping or switching to another SRS app.