There is a built-in feature to do this. Go to Dashboard -> Sitemap, then click the "Page Search" grey tab up top.
The list is sorted by "Date Modified" by default, you can also sort and search on other criteria if desired.

Thanks for that, but I was looking for somthing that would list it on the website as updates, as they would like vistors to know what is new so they can check out the updates.

You could easily make the built-in Page List block do this for you.

On your server, create a new directory named "page_list" inside your site's "blocks" directory.
Then copy these two files:

...into that new directory you just made, so you wind up with these two files:


Now edit the new copy of "controller.php", and find this line of code (should be around line #70 or so):

...and replace it with this code:


Now when you choose to sort the page list by "most recent first", it will sort them by their last-edited date instead of original creation date.