https://billhillapps.com/
Mostly from the time I was actively building and maintaining mobile apps. It's slightly outdated, but I'm still proud of the metro-style design.
As per my other comment, Swiss trains (especially SBB) are not as pleasant as they get credit for. I get a lot that "you know, in other countries it's much worse", and it reminds me of software hosting, where it was normal in the past to be offline occasionally. Then Google et al. came and showed that much more reliability is possible with good engineering. I think there would be a lot of room for improvement.
I'm a heavy public transport user in Switzerland, and even though it's almost a meme how reliable the trains are, reality is different. Yes, they operate in a way that make the stats look good (x% on time), but they take tradeoff to get there. E.g. they won't await connections if another train is a few minutes late. So you might have to wait for 30 minutes for the next one, or even longer if you're unlucky. And there's the occasional big incident, where you get stuck for several hours. I missed flights that way, even though planning in 3 hours of buffer. There is zero compensation in such cases as long as they bring you to your destination on the same day. Plus, several trains are regularly way too crowded.
Banks have stupid rules probably made by people who don't understand the matter. A relative recently got victim to phishing and gave away some of his banking details (fake e-banking login screen on a website). After locking the account, the bank said it would only unlock it after the phone got wiped, which obviously doesn't add anything in this situation.
Another pet peeve is that they prevent screenshots simply because they can, and it feels safer. I know, 3rd-party apps which can do screenshots etc., but this is fighting the threat the wrong way. And yes, it's partially the fault of the platform, which could just allow user-initiated screenshots. Or at least make it configurable.
I've done it before on a personal project and I was pretty obsessed with user experience. For example, I changed the way buttons work (because they were natively links with Cordova, which trigger upon tap, not "finger lift", like native buttons). Also, implemented some gestures to e.g. switch between pages (tab-style navigation). While not really in line with system UI (wasn't my goal), I think usability is quite decent.
That's still a bit risky as Arizona might just change its time zone definition on a whim. I'm an engineer on one of the big calendaring applications, and it's mind-boggling how often stuff like this happens world-wide, sometimes short-notice (a few weeks in advance). It regularly gives us headaches.