spaced repetition

 Spaced repetition  is a functionality often provided by apps and websites using a flashcard-based UI and used for improving one's memory.

IndieWeb Examples

 * none (yet?), but see also examples from "on this day"

Anki

 * Anki is a stand alone app with an associated web interface that uses a flashcard system

Mnemosyne

 * Mnemosyne is a flashcard-based program for improving memory

Readwise

 * Readwise pulls in highlights and annotations from books and online apps and provides spaced repetition functionality within its app interface or via daily email to allow users to review over their material.

Neuracache

 * Neuracache pulls data from apps like Notion, Evernote,and Roam Research, and TiddlyWiki into flashcards for spaced repetition
 * using sm2 algorithm
 * Anne-Laure mentioned it at 2020/Pop-ups/GardenAndStream, but doesn't recommend it at the moment

Memrise

 * Memrise is a language-based app and learning website that uses spaced repetition to teach new languages.

Duolingo

 * Duolingo is a language-based app and learning website that uses spaced repetition to teach new languages.

IndieWebCamp Sessions
The following camp sessions have mentioned or discussed some of this functionality:
 * 2020/Pop-ups/GardenAndStream
 * 2013/API All the Things
 * 2020/West/indiereads

Brainstorming

 * There are already IndieWeb sites which have on this day functionality which might be leveraged for providing this sort of functionality.


 * hovercards could be an interesting UI feature here