That's also what I think. For keeping on planes, and keeping the past version alive as a local copy. But honestly I didn't create it for that reason I think. I can't remember exactly now without using my power to think about it more...but basically I think I created it to just see if it was possible. I was doing lots of work in Chrome DevTools at the time and the idea suddenly came to me, and I wanted to see if it would actually work. This project has constantly surprised me by how much "legs" it has. People just love it. And the first version took me very little time to do. It's weird, other things that take a lot of time are not so popular. Utility or popularity with others has nothing to do with hard work, nor the amount of work, I think.
Ya, there could be so many use cases for this thing.
I thought of some evil ones, like I know some people at my company that would love to be able to browse an employees past browsing history at their convenience.
It doesn't really need to be "offline" for that to work, but I can see that playing into calling it a security procedure rather than blatant overstepping.
Having the ability to see the last week or so of my browsing history would have come in handy on more than one occasion.