A well-known dictionary for learners of English, which not only provides translations but definition of words, pronunciation and treasures. The treasure section provides synonyms and antonyms, real examples of words' uses.
It is a free and personalized way to practice English vocabulary. *There is a Web version as well as an App
Useful options: create 1) personalized word lists that can also be downloaded to study offline or access to already published word lists organized by topic or level. 2) quizzes or image quizzes
Grammarly is a writing assistant that offers you specific suggestions to help you improve your writing — and it goes way beyond grammar. Edit and correct your grammar, spelling, punctuation, and more. It can be installed on your browser too.
Translator
Translate text or even documents such as DOCxs, PDFs, PPTxs... The pro version also allows to target formal or informal styles. And it has de possibility to create your own glossary.
Extension /Tool
Wordtune helps you to rewrite and rephrase your writing. It is FREE and you can add its extension to your browser (Chrome). Feel free to use it through the website too, but you will need to login then.
Blogs
Check out several pages and profiles where some useful info, idioms o grammar are being shared for English Language Learners (ELLs)
She also has a website with some free resources https://www.mariaspeaksenglish.com/pages/recursos