After testing many French and German learning tools, these are my top picks!
Platforms & Apps
Lingoda Online Language Platform
Lingoda is a language learning online teaching platform, which offers online classes for all levels 24/7, in French, German, Spanish, English and Business English. I personally participated in the French Lingoda Language Sprint, and it immensely improved my grammar, speaking and conversational skills in just 2 months. I have also taken regular classes in German, to learn grammar and practice conversations.
LingQ App
LingQ is the best language learning app that I have found. You can learn languages from content that you enjoy, either by importing YouTube videos, books, articles into the app, or by scrolling through their existing database of content. You can easily learn new vocabulary, and review existing words with flashcards through the one app.
iTalki

I used iTalki to converse with native French speakers to practice my conversational skills, and improve my speaking. It was a lot of fun and really helped me to identify areas of the French language that I needed to improve on.
Language Reactor
Language Reactor is a Chrome Extension that functions on Netflix and YouTube, where you can view the subtitles in two languages at the same time, save unknown words, export saved words and much more.
French Books
Short Stories in French (Beginners & Intermediate Learners)

Short stories in French is by Olly Richards. He has two Short Stories books; one for beginners, and one for intermediate learners. I have read them both and highly recommend them! If you have never read in French before but want to, this is a great starting point.
Funny French Book (Suggested for B2)

Journal d'une peste is a children's book that I stumbled upon at a local book fair. It is hilarious, very creatively written, and features a lot of slang which I personally think is perfect if you are at a B2 level, or are wanting to learn more conversational French. The book is written from the perspective of a teenage girl, as if she is writing in her diary, so it makes for a very interesting story!
Harry Potter (French Translation)

If you have read Harry Potter in your native language, and you are already familiar with the story and vocabulary, trying to read it in French is a fun challenge!
German Books
Short Stories in German

Short stories in German is by Olly Richards. He has two Short Stories books; one for beginners, and one for intermediate learners. I am reading the beginners book in German and find it very helpful to learn new vocabulary, and see the language in context. I have read both books in French, and thoroughly enjoyed them!
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