Half-way through https://infrequently.org/2024/10/platforms-are-competitions/ by @slightlyoff I realized that yes, just this week I published an app that basically wraps around a popular estonian website, making it faster and easier to use on a phone.
Opening a website in a mobile browser, I always get that moment of dread that it has randomly-breaking javascript in it. State and focus are things of the past there.