The Tinycards website is HERE! Check it out at tiny.cards
It used to only be available for iOS, but now Duolingo has built a responsive web version it so it's easy to use on both computers and mobile devices! And you can log in with your Duolingo account.
Tinycards, the fun flashcards app by Duolingo was named one of Apple's Top 10 Best Apps of 2016, and selected as the 2016 Mobile App of the Year by ProductHunt. You can use it to memorize vocabulary, study for tests, learn the capitals of Europe; anything really. Learn by studying with user-created decks, or create and share your own decks.
Announcement forum post: https://www.duolingo.com/comment/21274493