I'd like to begin a forum to share any puzzles from the Puzzle Square JP website / app, and any other puzzles that fall under the description of paper or stateless. This would be separate to things like most modern puzzle video games which are stateful.
If you are not aware of what Puzzle Square JP is: it is a place to upload and categorize puzzles, whether made by yourself or by others, technically refered to as an "aggregator". You can create your own digital puzzles with tools such as puzz.link, pzplus, pzprxs, and other similar tools or forks of these tools. Then, you are able to post them by genre, difficulty rating, and with a description. Users can then search for, play, like, bookmark, and/or comment under that posting! The search feature is rich, it has the ability to filter by genre, by date uploaded, and other options too, and if you create an account you are able to mark a puzzle as solved once you do solve it!
So, sharing any links from Puzzle Square JP might be useful and make it easy for anyone here to share, play, and save cool puzzles! I love to browse it and to find incredible puzzles worth sharing with others, I highly recommend it. Happy puzzling!