note.com : A blog website where you can read journals, commentary, and essays about basically any topic.
https://kids.gakken.co.jp/ : An educational website for answering questions for kids. There is a variety of interesting topics like「友だちのあくびは、なぜわたしにうつるの？」Furigana is also included.
https://reader.ttsu.app/manage : A website where you can import Ebook files and read them in your browser. This is really useful because you can use addons like Yomitan to quickly look up and mine cards. It also tracks your reading stats which is pretty useful.
Feel free to suggest more in the replies.
by brentonlop