Coding Languages

• HTML Cheatsheet - Can't remember what a certain thing does? This site's got 'ya covered. Also has similar versions for CSS and Javascript.
• MDN Web Docs - A repository of information regarding HTML, CSS and JS among others. Contains tutorials and solid explanations of certain tags and functions.

Graphics

• Asterism - (JP) Cute backgrounds, frames and other visuals.
• Bon's Graphic Collection - A large collection of gifs and pixel graphics found across the web and compiled here by Bon/Plumbum.
• FoolLovers - (JP) A site which contains a lot of cute sozai, and even has a section for premade templates.
• Lapin's oldweb gfx hoard - A curated collection of pixels, backgrounds, and other cute things to decorate your site with.

Templates

• EggRamen's Layouts. Many mobile friendly site layouts for those who are just starting out. Easily customisable, and very fun to use.
• FoolLovers - (JP) As stated previously, this site has multiple free to use templates

Games

• MakoTools - Fanmade resource for Ensemble Stars akin to Schoolido.lu, used for tracking cards and when events are happening on the global server of the game.

Misc

• Catppuccin - A community-built soothing pastel theme which can be used on a variety of different apps and websites! I use the Macchiato theme on both VSC and Anki.

• 10Ten Reader - Browser extension which is useful for looking up terms quickly while navigating the web. Also translates Japanese era dates into Gregorian calendar dates, and converts currencies.
• Anki - Open-source flashcard application which is popular with language learners due to the ability to both import and create personalised flashcard decks. Can be used for basically anything, though.
• Shirabe Jisho - (iOS only) Dictionary app which also deals in flashcards and specific vocab categories for dialects & slang.