There's not just the PPL Confuser but also a very good book called Q&A for Private Pilots by Holden & Brett. I think that's what it's called and who it's by (I do know that it was updated by Dorothy Hockings) but until my instructor gives it back, I can't be certain. I found it very useful and a good measure of the real thing.
I would reiterate what others have said. Try the Trevor Thom books, make notes as you work through and try his practice questions at the back. These are not multi-guess but where you actually have to write an answer but they test your understanding better.
Cheers
Whirlygig