You know those websites that load a little bit of the page as you scroll, I want to search the whole thing !

First it would be something that autoscrolls the page without needing me to keep the page down button pressed down for the entire duration, which can be a lot. I want to do other things while this happens

Second, some websites, like facebook, actually UNLOAD from memory the data as you scroll further, defeating the simple scroll down. So, once the first one is done, I would like something that aggregates the entire page and loads it in a static second tab and/or saves it to a single file ?

Is there anything like that, yet ?