TOEFL speaking test is an interactive activity. You not only need to have the correct answer but have to speak out the answer in the right way. So, the timing practice is critical.
The practice page imitates the mode of TOEFL Speaking Question 1 to offer timing exercises for any questions you load. In addition, it has 72 built-in common questions to let you practice on demand.
There are four actions: Start, End, Skip, View to help you manage time and exercise more efficiently. But these buttons don't exist in a real TOEFL scenario, in which you must do exactly like the instructions. It's why sufficient timing practice is essential to get a good score.