You can comparison shop among the various downloads and find the perfect one for you, then take a trial run and make sure it is actually the one you want before you plunk down any hard, cold money.
Take the car for a trial run to see if you like it.
她提前一年参加考试，算是 (正式考试的) 试考。
She's taking the exam a year early, just as a trial run (for the real thing).
It was sort of like a trial run for the school camp.