It does have some spelling mistakes, small typos but it is very user friendly and the fact that it has pictures makes it more interesting. I like how you don't get the whole text but each paragraph separately and the question in turn at the bottom. I like how it has immediate feedback. And, I really find the highlighted words to be useful.
Average Not much helpful
Nice! I have used the website for 1 year and look forward to seeing the app for a long time. Very useful for Ielts learner.