It's very interesting. I tried similar approach just by giving some input text to Stable Diffusion and the images are not satisfactory. So I didn't pursue the idea. Because making a site with serious content, people are very reluctant to get in. But satirical or comical way of telling the stories are attracting them very fast. Like Tick Tok videos.
At least the way it works on iOS, iOS is supposed to keep track of whether you purchased that purchase or not (that type of purchase at least not the 'buy x items' consumables), and require apps to have a 'Restore Purchases' option you can click to load which items have been bought and restore the state of your app.
At least in theory, maybe there's been a few cases where it hasn't worked. I'm not aware of any, though.
I don't know how that works on Android. That might not be supported.
I created a vehicle plate recognition system before ML got cool, but I can't get any ML job with my less than bachelor degree (associate? dunno how to translate) here in Brazil. I think there are only 2 positions open for machine learning less than 100km from where I live.
You do it the same way exploit writers do. Attach a debugger to the process, find the memory address of the resource you want to modify, overwrite the address with the address of the modified resource you want to execute. You could also just use the debugger to force the program to execute functions with arguments you specify, that way you don't have to worry about mucking with the memory.
Usually you'd create a dynamic library that interposes a function, so you don't have to much around with using a debugger. This way you have a persistent modification that's much more resilient to changes caused by app updates. Exploit writers generally have different goals: their thing only really needs to work once, and only with the current configuration, since usually the bug they're relying on gets patched in the next version.
Also, depending on the platform, if a native application is following the platform guidelines, then quite a lot of things you want to change might be located in data files or "resource" section of the executable.
I haven't been messing much with Windows executables for quite a while, but back in the day, I'd "improve" many programs by just editing their resources.
It currently uses open-ai models for the contents and stable diffusion (using the AI Horde) for the images.