TestHelper frees you from having to calculate how are you doing during a test and lets you focus on the test itself.
When taking timed tests you are probably assessing things like "am i on time ?" "how many questions per minute do i have to answer ?" "how many questions do i still have to get right to pass"
TestHelper visually guides you trough all those assessments and tries to give you a concise and helpful picture while you are taking a test with minimal intervention.
Before you start a test you are asked to enter the test parameters, during a test you only optionally need to press the +1 button when you are sure you made a correct answer.
TestHelper also helps you in retrospect after you finished a test to see how well your assessment corresponded with reality.