I found
AirQuiz - Online Practice Examinations for Pilots very helpful however, some questions are out dated on the site and for obvious ethical reasons they do not contain any active questions.
They say a year long licence however they have never ended anyones licence and so should be good for as long as they stay online.
They email you the exam marked. And it gives you areas to study up on if you did bad in a certain question.
Please note however even if you get 100 on the exams after a while, then take the school mock paper as these become unreliable for scoring after a while.