Banned Bookshelf
I've built two directory app websites as a fun way to track some topics that I’ve been interest in. One is https://bannedbookshelf.com which lists books that have been banned for whatever reason, or have been yanked off Amazon for being too ‘spicy’. The other one is https://fangamesdb.com which tracks the decompilation and recompilation scene which is exploding now with AI reverse engineering tools.