Zettel.cards by Chris Dawson

Login to zettel.cards. Then, from any web page, select text and instantly create zettelkasten cards. Text is used to automatically create zettelkasten cards with a set of choices. Zettel.cards are available to review using the leitner algorithm on zettel.cards or automatically available as git repository on git.zettel.cards for easy versioning. You can also pull in other high quality decks or individual cards to augment your card decks.