Service for test versions of the site?

Question

Software testing

The bottom line is this, I found an article on Habré for a long time about a service, the essence of which is as follows:
1. A test version of the site is being created (I don’t remember a working or just a layout, the functionality seems to be available)
2. There is an opportunity right on the element of interest to you, make a note, circle marker, etc. Moreover, it is available in real time and not only to you.
Actually the question itself is, are there such services? I suspect that they are all paid, but the main thing is the functionality.

Answer 1

www.invisionapp.com for example

Answer 2

https://redpen.io/