Hacker News Reader

Lichobile[0] (lichess[1] mobile version) is also made with mithril.

There's also https://flems.io a snappy web playground with an open source embeddable core[2] ( shameless self promotion :P )

[0]: https://github.com/veloce/lichobile

[1]: http://lichess.org

[2]: https://github.com/porsager/flems

Aside, Flarum's scrubber/scrollbar is brilliant and a massive upgrade to how you have to navigate a traditional message board like phpbb where you kinda guess at arbitrary pagination til you're where you want to be.

Good example of using a SPA to improve UX of a "document-based" app.

Another example of this sort of SPA improvement is when clicking on a list-view item brings up an overlaying modal of the item-detail page which is nicer when user is browsing rapidly.

Not to mention the wonderful testing utils which ship with it https://mithril.js.org/testing.html