Now that a month has gone by, I've unlocked this post with a video of my prototype spaced-everything platform: https://patreon.com/posts/36827866
(still experimenting with what makes sense as Patreon-only, for how long, etc…)
Yes, I built a reusable FlashCard widget that any blogger / writer / publisher can embed in their web content. The idea was to use localStorage to keep user's progress for spaced-repetition, so that no signup etc is necessary. Here: