If software quality includes a goal like “delivering what we promised on time and on budget”—and it should—then testing is essential to meeting that goal.
Normally, testing is just about finding bugs—“defect removal”—which is worth doing. But testing can also be about increasing quality in the eyes of the only people whose opinion matters: Your users.
Automated QA testing tools are products that start an application, feed the application’s UI some inputs and then check the result of processing those inputs. Which ones are worth taking a look at?