Started Ok - but DO NOT recommend now.
My daughter used Sparx extensively, while attending a large state school for Year-7. It was good for her, partly because the classroom education was un-streamed, and still covering year-5 material etc (= boring). She scored the highest LP points of anyone in the year.
For Year-8, she moved to another, smaller school - that also uses Sparx. BUT it has proved impossible to transfer the file. Sparx Learning have not responded to any of my support requests. The School Maths departments have also tried, but been told - "No, it can't be done". Apparently, transferring a simple, digital file is too difficult for them.
She, she will have to start all over again, which is quite crushing for her enthusiasm ☹️.
Sparx Learning tout their "AI question-setting". This does work, but it's haphazard and slow. Certainly, it would require the student's entire progress file, and not just a current score /level. So, until it improves, their AI is of limited value.
For us the biggest problem is the complete lack of support and absence of empathy for kids /users. And the refusal to go out of their way, even a little, to help a keen user. Ours may be an "edge case" - but it indicates much deeper problems. If you have a choice, PLZ select other applications, and avoid Sparx.