a bit unsorted, but here's what I can remember off the top of my head.
• https://homestuck.net/ - you might know it or not, but i think its the best archive with HS resources. old homestuck themed games, sprites, cosplay tutorials, you name it.

• https://michaelbach.de/ot/ - 152 Visual Phenomena & Optical Illusions with explanations by Michael Bach

• https://warningsigngenerator.com/ - Warning sign generator

• https://blinkies.cafe/ - blinkies maker searcher and generator (blinkies is a small gifs to decorate blog website et cetera)

• https://paint.js.org/ - old ms paint online