Nearly Unusable
While I can tell that the creator(s) had nothing but the best intentions. The questions are written in a way that makes them hard to understand and with improper wording. All of the above and none of the above are usually 2 of the 4 answers to a question that clearly has a single answer. The developers seems to understand the subject matter, but this is simply poorly executed. For 3 extra dollars, you can unlock many more questions, but I’m not sure it will benefit those looking to gain an understanding.