In this thread multiple answers say Anki/spaced repetition.<p>https://news.ycombinator.com/item?id=20920635<p>Spaced repetition users, what are you using it to learn and what have the benefits been?<p>Especially interested in people using it for things other than school/studying/grades.
Mainly for learning the letters of the greek alphabet. I have an Anki deck for that. Why? Because those symbols are so frequently used in math, and I instinctively try to subvocalize mathematical symbols in my head when I see them, and if I see a symbol I can't "pronounce" something in my brain puts an "ABORT! ABORT!!!" message in the queue. So even if I don't know what, say, "xi" means in a given context, if I can at least have the pronunciation as a placeholder, parsing can continue, and I can look up the details after I've read the passage I'm working on.
I used it for quickly acquiring vocabulary in multiple languages when I was living in Europe, and later when I was learning enough Japanese to get by during my vacation in Japan. It makes acquiring five to ten new words a day sustainable.