I wanted to share some valuable resources that have aided me in my Japanese learning journey. I'll continuously update this post with additional resources that I find useful, and I also encourage you to share your own recommendations. Together, we can build a comprehensive list of tools to support our language learning endeavors.
Web and phone apps
Anki - Spaced repetition based flash card app. Can be downloaded on Android, iOS, and accessed through the web. Highly customizable, while also allowing one to use decks created by other users. There are also useful plugins which can enhance your learning experience. https://ankiweb.net/about
Platforms: Android, iOS
Renshuu - A Japanese language learning application that helps gamify the process, while offering flexibility and variety in selecting your own difficulty. Recommended by @ZILtoid1991 https://www.renshuu.org/
Platforms: Android, iOS
Jisho - An online Japanese dictionary. You can install an extension which enables the display of the pitch-accent patterns for any word, which will be linked in the next section. Jisho is also available on Android, iOS, and as a Progressive Web App (PWA). https://jisho.org/
Nihongo – Nihongo is an offline Japanese dictionary, flashcard app, and reading assistant, designed to make the best use of the time you dedicate to studying Japanese.. The app also includes audio recordings from native speakers for many words, instead of relying entirely on text-to-speech. Recommended by @bobob
iOS https://apps.apple.com/us/app/nihongo-japanese-dictionary/id881697245?l=en-GB
https://www.wanikani.com/ - Kanji-learning app that teaches radicals, kanji, and vocabulary. Lessons and reviews are available, and utilizes a Spaced Repetition System (SRS)
Browser extensions
jisho-pitcher - Adds a visual depiction of pitch-accent patterns to words and phrases found on Jisho.
Note-taking apps
Notion - A robust, highly customizable note-taking app that has a mobile and web version. You can tweak things to your preferences, or use premade formats provided by Notion or other users. It should be noted, that this does not work offline. https://www.notion.so/
Platforms: Android, iOS, Mac, Windows
Obsidian - Another note-taking app with a mobile and web version. Syncing is a paid feature, however, you can upload your vault (collection of notes) online to access them anywhere. Offers plugins created by the community which enables new features. This application does work offline. https://obsidian.md/
Platforms: Android, iOS, Linux (AppImage, Deb, Flatpak, Snap), Mac
Websites
Irodori - Free digital textbook and workbook series with native audio recordings. The resources included consist of vocabulary, grammar, kanji, hiragana, katakana resources, and more. https://www.irodori.jpf.go.jp/en/about.html
NHK News articles - Offers simplified news articles that provide cultural and historical insights. The web interface allows users to easily toggle furigana and listen to the articles being read aloud, albeit with a robotic voice. Each article is a simplified version of a full-fledged NHK news article, with a link to the original content provided. This website enables a smooth transition for beginners to explore more advanced news articles as they become more comfortable with the simplified ones. It encourages progress through gradual learning and understanding. Recommended by @bayaz https://www3.nhk.or.jp/news/easy/
Textbooks
Genki - Integrated Course in Elementary Japanese is a study resource for people who are starting to learn Japanese. It is designed to comprehensively build communication competencies across all four skill areas—listening, speaking, reading, and writing. https://genki3.japantimes.co.jp/en/intro/
Regarding the dictionary app: I prefer the app Nihongo on iOS. Looking up words works similar to Jisho, but the UI is less buggy. The app also includes audio recordings from native speakers for many words, instead of relying entirely on text-to-speech.
I just noticed that part of the description for Nihonho in the post is in German. Maybe because the link I shared was for the English version of the AppStore? Anyways, here is a link that hopefully provides the English description. It would be nice, if you update the link and text in your post.