Hi,
I made a new toy 'Baeuda' (means learn in Korean) recently, that allow me to learn Korean by creating cheatsheet notes in Joplin, and, with that script, create decks/cards in Anki
basically, anki is a card system with question and response, that displays the question one by one, you try to guess the response, and then press the button "display". If you feel you correctly reply, then you press one of the 3 buttons something like "hard (back in 10min)", "good back in 1day", "easy back in 4days" to see the card back at that moment. Then the more you feel ok with one card the more you can postpone the next time you will see it.
so this system (anki) can be applied to many others domains and anki is available on smartphone too so you can manage your cards on the desktop and sync cards/decks to be used on your mobile.