There's another benefit to opening this kind of functionality to apps - it's very friendly towards developing interfaces that are more friendly to the disabled.

There's another benefit to opening this kind of functionality to apps - it's very friendly towards developing interfaces that are more friendly to the disabled. I have certain disabilities where specific types of UI designs are basically unusable to me, and without the ability to customize them, I kinda just cannot use them (unless they provide an API as an alternative).