My son used this site during Covid shutdowns last year, we read both English and French, he progressed very nicely, he worked his way up from the basics of reading to more complex reading. No complaints, it is a helpful and they made it fun to read - my son did a great job and continues to be good reader. He posted a youtube video of his experiences using the fun site:
https://www.youtube.com/watch?v=RnqrmOYjM1E