And this is fundamentally different from the ppl confuser/simplifier in what way exactly?
This app does what those books did, no more, no less. Some flying schools sold the books to students!
Was there as much gnashing of teeth about these publications? Or were they o.k. because they were in book form, from a "proper" publisher?
Fact is, even if you are using a question bank, you are reading and learning the study material.
And probably (hopefully in fact if the exam is set well) concentrating on the parts of the syllabus relevant to real word aviation.