This post by Peter Merholz from 2010 stuck in my head:
Toddlers love the home button. Being the only physical button on the device, and thus the only the that provides tactile satisfaction, toddlers press the button all the time. Particularly while using an app they really like. And they don’t realize that pressing this gets them out of the app. And after they press it, they then look at you, as if to suggest something is broken, and you need to help them.
On a Jailbroken iOS device, IncarcerApp gives users a way to solve this problem, by temporarily disabling the home button on a phone.
This tweak is, I think, a perfect illustration of why users might wish to legitimately jailbreak their device. The term Jailbreaking carries negative connotations. It suggests a link to piracy, copyright theft, data theft, and the spreading of malware. But the tweak described above is about none of these things: It is about a common design/usability problem that many people encounter. Why shouldn’t these parent-users have control over the core functionality of their devices, so that their children can use the device for entertainment and education? Why does Apple place barriers to this kind of action? I would bet that if the functionality provided by IncarcerApp were available by default on iPhones and iPads, educational apps for very young children would become more popular.