MonkeyDev VS InjectionIII

I can't read a lot of that project, but what I can doesn't look like you'll be able to do that on an iPhone. If you look at the installation section, it's expecting you to be building this on a mac: https://github.com/AloneMonkey/MonkeyDev/wiki/Installation (that isn't called out explicitly, but it's implicit in the commands they're running). "Easy to install" in this case seems to be for someone who is familiar with writing custom iOS applications and has a development setup for that already.

Theos is the easiest way to do it imo but you can still use Xcode with something like MonkeyDev if you want to. Either way you'll need to install theos

Those of you that prefer UIKit, are you defining layouts programmatically? If so, do you use other tools like Injection to help ease this process?

Good news is you can hot reload the simulator using InjectionIII. It's what the appcode documentation say to use to get a similar experience to previews.

It isn't going to be easy, but I do want to try my hand at making one someday. In the meanwhile you might want to check out Echo and InjectionIII for a glimpse into what might be possible.