https://en.wikipedia.org/wiki/Tivoization
https://apple.stackexchange.com/questions/6109/is-it-possibl...
https://github.com/SimHacker/micropolis
However there's nothing stopping you from running one of the versions of Micropolis that's been rewritten in JavaScript to run in the web browser (because it's distributed via the web instead of on the App store), or contributing to those projects to make it run well on the iPad.
Side note: I went to college with one of the people that ported the original version to the Amiga in the late 80s. He told me the cheat codes, which was handy.
Ah, I always knew there was some anti-Tivoization in there, but didn't really dig into what it truly covered. So in other words, you could have a highly successful iOS app you sell, that you release under the GPLv3, and nobody should be legally allowed to publish it under the official App Store. They could only potentially contribute bug fixes, and licensing their commits back to you sounds a bit like it would need another license from their code.
That kind of sucks that the App Store is not technically compatible, I would of thought due to JailBreaking it would of been technically allowed.
So Apple bans GPLv3, because they do not permit you to do what you want with your device, the device does what Apple wants and permits you to do with it.
They could also port it to Android and release it there for free, or even sell it there (while offering all buyers the source code, to comply with the GPL)
https://itunes.apple.com/us/app/pocket-city/id1330451888?mt=...
It has NO microtransactions or ads or other annoying mechanisms.
Oh god... I'm old... =)
I bought the edition that came with the Sim City Urban Renewal Kit, which was a way to create your own buildings using the graphic editor. It even had support for animations using palettes! I had a grand ol' time creating gawdy, neon-brutalist monstrocities to shove into my cities.
[1] http://ebay.co.uk/itm/202526513876
[2] https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=nes+control...