Here is a site with lots of instruction and practice in grammar and grammar terms.
Here are a few places to go to work on your spelling:
https://en.oxforddictionaries.com/spelling (This one is from Oxford Dictionary. It has various areas of instruction to help you understand English spelling.)
https://howtospell.co.uk/spellingquiz.php (This site has a lot of practical practice with answers.)
http://www.manythings.org/e/spelling.html (This website has a variety of practice and games to help you improve your spelling, including specific problems like l/r.)
Here’s a link to some common English mistakes and how to fix them.
If you are not sure how to structure an essay, this might help. It allows you to put in your main ideas to get an organized outline, and then you can use the outline to write an essay. Of course, on your real exam, you will need to make your own on paper 🙂
Some IELTS candidates have trouble understanding the Australian accent. Here is a link to TEDx videos, some from Australians, that you can check out:
And then there’s this little video of a Canadian and an Australian comparing their pronunciation:
Here is a link to some useful phrasal verbs.
Here are two sites that may help you with essay writing, specifically focusing on vocabulary.
This page focuses on cohesive devices: https://www.oxford-royale.co.uk/articles/words-phrases-good-essays.html
This site has a couple word lists you can download and suggestions on how to use them: http://www.dcielts.com/ielts-essays/vocabulary-a-list/
This website has a lot of examples of everything, really. It’s not all worthy of a band 9, but there is some good information. This example is quite strong, although the use of paragraphs is not completely logical.