Shout out to a rare example of a corporate phone app done well: Delta Airlines' phone app is useful, more than just a webpage, doesn't have ads, and can be used without signing up for an account. If you have a ticket, you put in your info and it *just works* for the duration of your trip and provides valuable information and updates.

I don't know how the engineers managed to keep the executives from inserting dark patterns, but kudos.