WORDLE: play one a day online at
WORDLE ARCHIVE: play all previous Wordle words at https://www.devangthakkar.com/wordle_archive/?231
PLANET EBOOK: good source of free public domain books
PDFDRIVE: good source of free books
The Free Dictionary: good for vocabulary, flashcards and challenges of various sorts. I am a registered user.
Merriam-Webster Dictionary: I'm a registered user on this site.
Dictionary.com: I'm a registered user on this site.
The Cambridge Dictionary: I'm a registered user on this site.
Site maintains a blog: https://dictionaryblog.cambridge.org
Smashwords self-publishing website and ebook site (some free and the rest relatively inexpensive)
EPDS seems to be a source of books on a variety of subjects
Vocabulary.com this site allows you to set up classes and assign quizzes, challenges etc. created by yourself or others. It's free with up to 50 students per class.
Here is a link to my Google Document on vocabulary, collected from Dictionary.com (accessed using Facebook). I also have currently over 700 words on my Kindle that I've marked during my reading. The words can be practised using a flashcard system that shows an example of each word's usage and allows you to mark a word as mastered if you know its meaning. There is a way to export the data but my first attempt at doing so failed, even though it seems straightforward enough (notes on how to do it have been saved in Google's Keep) .
I try to keep track of what books I read via goodreads.