Where are my decks stored, and can I lose them?
In your browser's localStorage, under the key cleanor-flashcards-v1. Yes, you can lose them: clearing your browsing data, a cleaner extension, a browser reinstall, or a private window closing will all delete them with no warning and no recovery. Use Export JSON on anything you have spent real time on.
How do I move a deck to another device?
Press Export JSON on the deck, move the file across however you like, and press Import JSON on the other machine. There is no sync, so this is a manual copy, but it does mean you own the file and no service can lose it for you.
Why does a card I marked known keep appearing?
Because the known flag is a marker, not a scheduler. It counts toward the 'x of y marked known' line and puts a tick in the card list, but the card stays in the study cycle. Delete it if you are truly done, or press Reset progress to clear every flag and start a fresh pass.
Does this do spaced repetition like Anki?
No. Spaced repetition schedules each card for a specific future day based on how easily you recalled it, which is the mechanism that makes it so much more efficient than plain review. This is a straightforward flip-and-cycle deck with a manual known flag. It is good for cramming a small set; it is not a long-term retention system.
Can I put an image or audio on a card?
No. Both the front and the back are single-line plain text. For vocabulary, definitions, formulas, and dates, that is enough. For anatomy diagrams or language pronunciation, it is not, and you want a dedicated app.
What does Shuffle actually shuffle?
The study order, not the deck itself. It reorders the sequence you see cards in and jumps back to the first card, but the deck's stored order and every known flag are untouched. Shuffling before each pass is worth doing: reviewing cards in the same order every time lets you memorise the sequence rather than the content.