The up to 3 apps per device stay but cannot be opened after 7 days until refreshed.

And "whatever code you want" here excludes JIT compilation, or as I understand it memory that is both writable and executable, as your app would require a special 'entitlement' from Apple.

You actually need a paid account, even for local installs, if you use certain tech, like NFC

Seriously? I have a custom Android app that I use. It's mostly vibe coded now, which I'm a bit embarrassed about, but demonstrates that the bar for custom software is very low at the moment and getting lower.

I considered getting an iPhone to replace my S-series Samsung, the only reason I stayed with Samsung is for the S-Pen. Had I gone with iPhone I would not be able to write and run my own software? That's absolutely ridiculous.

Strictly speaking, I can't, I don't own any Mac nor planning to do so