Watanoc.com stands for 和楽しい日本語
It looks like the bulk of the text was written in 2016 but there is plenty there to read. Texts are tagged for reading levels N5 to N3 and have a built in dictionary function as well as translation into English, Vietnamese, and sometimes Chinese. Some texts have audio accompanying them.
Texts focus on aspects of Japanese culture (food, calligraphy, manga). You have the option to turn on/off both the subtitles and the ruby in the subtitles. This is a really good way to improve your listening skills. While the responsible organization isn’t listed prominently, in the about section it says that it is the Japan Foundation, Kansai Center.
Matcha Easy is a website with articles focussed on travel to Japan. Lots of lovely photos, travel tips, all written in easy Japanese.
niponica is a multilingual web magazine on the Web-Japan website (sponsored by MOFA – the Japanese Ministry of Foreign Affairs). There are a few wonderful things about this web magazine. You can read it first in English to find articles you want to read in depth. You can switch over to Japanese to read it (and use a pop-up dictionary if you want) and/or the pdf version of the Japanese text contains furigana over the difficult words. This would be my preference for reading slowly and carefully. I often recommend this title and its predecessor to upper level undergraduates.
Japan Video Topics is also sponsored by MOFA. The videos are available for download or on YouTube. Remember to turn on the closed captioning if you are watching the Japanese version. Don’t look for gritty views of Japan in these videos that are sponsored by the Japanese government, but they are good for listening/reading practice and useful for learning more about Japan.
Kids Web Japan has a Japanese interface. There are lots of short essays written in clear Japanese with furigana. Should be good for students reading around N4-N3 level (?)
Students who love folk tales should add Hukumusume’s Ohanashi kikasetene to their reading/listening repertoire. There are fairy tales, folk tales, ghost stories, and Edo witty stories all with both text and audio. Great for students who are wanting to build up their comprehension skills in small bites. And, because this is an old-fashioned html site, you can use Rikai as a mouse-over dictionary to help you with the words you want to check.
Wasabi is an online Japanese instruction website that also provides quite a bit of free information. For example, Japanese Radio Programs has a rating of JLPT N3 and you can choose to listen to the audio at a slow speed or a normal speed. They have also created some graded readers set at JLPT N4 with the same audio options.