Animal Photo References » Rotate a 3D head to get photos at that angle.
Creating Pixel Art » A complete tutorial about the basics.
Body Visualizer » Enter body measurements to generate a 3D model.
Ezgif » Split a gif animation into frames.
How To Practice Art » A short but helpful comic.
IMGonline » Create seamless textures in browser.
MiniBoss' Pixel Art Tutorials » Tutorials on making and animating pixel art.
Reference Angle » Rotate a 3D head to get photos at that angle.
The Etherington Brothers » Hundreds (literally) of tutorials on drawing.
Visual Height Comparison » Enter measurements for height comparison.

Archive of Portuguese Legends » Read Portuguese folk stories. Portuguese only.
Classic Short Stories » Read short stories for free in your browser.
Fantasy Worldbuilding Questions » An in-depth guide to creating worlds.
Rhymer » Find rhymes for every word.

Animelon » Watch anime with japanese subtitles and english translation.
Babadum » Vocabulary games in many languages.
JapanDict » My favorite online dictionary.
JLPT Sensei » JLPT grammar explanations, vocabulary and kanji.
Natively » Find books, movies and TV shows based on your JLPT level.
Niai » Find similar-looking kanji.
Tadoku » Free reading materials for different proficiency levels.
TanoshiiJapanese » Another dictionary; very useful for verb conjugations.
Weblio » A Japanese to English dictionary with many examples.
Verb Conjugation Guide » All the main verb conjugations explained.

CBox » Free chatbox widget.
CodePen » Test out your code.
CSS Layouts » Premade CSS codes to create many different site features.
Floras » A ton of HTML codes for many different effects.
The Doll Archive » Many resources and helpful links.
Web Code Tools » Useful HTML/CSS code generator.
Word to HTML » Converts Word-style documents into HTML.

Adventuron » Create text adventure games in browser.
Dave's Mapper » Create dungeon maps in browser.
Emofuri » Free animation program. Japanese only; see an English guide here.
Freem » Download free japanese indie games.
Tiny Tools Directory » A comprehensive listing of small, free, or experimental tools.
Twine » Create text-based games with simple coding. Browser version available.

Explorable Explanations » Learn and explore different topics through interaction.
Google Feud » Guess the autocomplete searches.
Little Alchemy 2 » Combine elements to create new ones.
Picrew » Many character creators and dress-up games.
The Forest » Visit a random website.