The free (also trial) version of this software says it will work with only "one browser at a time." This is (intentionally, I think) misleading. The trial version will actually work with only one browser, and that browser is Safari. You pay for the pro version to test it in Firefox, Chrome, etc. I use Firefox, and have no real assurance in the rigid testing that the way it behaves in Safari (which I never touch) will be the same in Firefox—or even, after the misleading come-on, whether it will work in Firefox at all. This bodes poorly for user-friendliness. Too many variables, so little time!