[geofft]

Side note, several of these restrictions are App Store restrictions and not OS restrictions - i.e., with Xcode but without a jailbroken device you can run custom browsers just fine. But there's no market / user base because Apple limits how many devices a developer can install test versions of apps on, so nobody has bothered to build such a browser, as far as I know.

I'd love to see an open-source project that helped you get set up with Xcode on your own device (or your favorite cloud Mac host... I wonder if you can make Travis work for this, honestly) with your own developer key, so you can build non-App-Store permitted apps for your own small number of iOS devices and not run into the private distribution limit.

[Nullabillity]

That's a distinction without a difference, since (as you mentioned) iOS is set up to discourage third-party distribution at every turn.