I frequently look at the DOM of webpages, so that I can bend them to my will.
There's always some things about practically all websites are frustrating. I fix that with custom CSS and/or Javascript that runs when I load specific sites that I use frequently. I can turn a cluttered site into a streamlined site for my needs. I also block a lot of ads, popups and other annoyances this way.
Oh there's another. The web is so miserable nowadays, I waste so much time on this. You don't happen to open source your stuff do you?