Paid version includes a package of 180 questions categorised in three difficulty levels. Answer images are shuffled every time you start a test therefore providing for 720 possible questions. This is one of the advantages of using this application as compared to paper tests where you are most likely to remember the solution from the last time you saw the question.
You can switch off the timer easing the pressure to determine the correct answer. To answer the question you just need to tap the answer and then tap on the submit button. You can also choose study mode which provides special features to help you better practise find the correct answers. This application does not require internet access. Once installed on your device, you can practise anywhere you like.