Feel free to contact me on twitter @jbtenmatay if you want to include a tool or resource.
Dictionaries
Weblio Japanese to Japanese Dictionary
Weblio Japanese to English Dictionary
Weblio Japanese to Japanese Thesaurus
https://meaning.jp/ - Etymological J-J resource. Helpful for [word]とは searches.
goo.ne.jp Japanese to Japanese Dictionary
goo.ne.jp English to Japanese Dictionary
https://www.dictjuggler.net/yakugo/
http://nihongo.monash.edu/cgi-bin/wwwjdic
https://www.kenkyusha.co.jp/modules/08_luminous/index.php
Tools and offline dictionaries
http://qolibri.osdn.jp/ - browse and search EPWING format dictionaries (can be found online)
https://takoboto.jp/ - Available both online and offline
https://kanjitomo.net/ - Kanji OCR Tool
fugashi - Japanese tokenizer and morphological analysis tool
Japanese Sound Effects (SFX)
http://thejadednetwork.com/sfx/
Hentai and Non-Hentai Sound Effects and What They Mean (PDF)
https://www.japanpowered.com/anime-articles/manga-sound-effect-guide
http://mangastudies.com/sfx/index.php
Name kanji reading and katakana names
https://www.kanshudo.com/searchn - E-J name kanji lookup
English writing tools
WordWeb - Offline dictionary and thesaurus
https://capitalizemytitle.com/
https://titlecaseconverter.com/
The Chicago Manual of Style Online: Hyphenation Table
The Art of Writing Effective Queries
https://www.freecollocation.com/
https://www.rhymezone.com/ - Not just a zone for rhymes.
Merriam-Webster Dictionary and Thesaurus
https://writingcenter.gmu.edu/guides
Netflix English Timed Text Style Guide
Regular Expressions (Regex)
Regular Expressions: an Introduction for Translators
English resources for reading
List of Generic and Genericized Trademarks
Appropriate Terms to Use About Disability
A Fair Point Ensuring Gender Neutrality in Translation
Edging Toward Japan: Just how gender neutral is Japanese?
Queering Translation, Translating the Queer: Theory, Practice, Activism
Translation by Example: Principles for Minimizing Errors
Are your Japanese translations sounding robotic? Opt for the human touch.
https://legendsoflocalization.com/
Literary Translators Comment on Localization & Re-Translation
Can a Translation Be Better Than the Original Book
Capcom’s quest to translate The Great Ace Attorney for Western audiences
What the different カッコ (quotation marks) in Japanese are and how they're used
(Quora) How do you spell out sexual moans
List of Japanese Abbreviated Words and Phrases
The possibilities of research on fujoshi in Japan
Game Localization
Project Management in Game Development
Best Practices for Game Localization
Game localisation: unleashing imagination with 'restricted' translation
Redundant Translations in Games & Anime
Videos talking about Translation
Tackling Translation: Media Localization Across Mediums (EN/日本語)
Thinking Outside the Panel: Critical Thinking for Simulpub Manga Translation
Manga lettering
Other resource lists
J-E Resource Sheet by @usagiko
Living Japanese Slang Dictionary by Wes Robertson
Japanese Online FPS Game Terms Flashcard Set (Starter Pack) by Tomoyo