When you use Drive4you, you are guaranteed a good and thoroughly tested material in collaboration with the Danish Driving Instructors' Union.
You get access to a digital theory book, which in the Danish version has a reading function for car and tractor. There is 27 theory tests and opportunity for self, to form more if desired. A larger collection of theory films, both as teaching and as subjects. You also have your very own progress statistics.
Danish Driving Instructors' Union's digital theory books, are full syllabus books, on over 250 pages for e.g.. car.
You can with great advantage buy access through your driving school and make a good bargain.