Al your changes will be deleted after 5 minutes. So it is possible that you lose your own comments or that you see comments from other testers.
Test the introduction overlay.
With the introduction overlay you quickly explain your client how it works.See demo
Test a one page website
For this example I used the home page of the old Apple website.See demo
Multiple design's combined
Here I also used the home page of the old Apple website, but I added two more pages.See demo
Password protected MockUp
This MockUp is password protected. The password is 123.See demo