[huebnerob]

No, definitely not. Apple recently restricted apps' usage of URL schemes to check whether other apps are even installed on the phone.

It's possible they could be doing something really esoteric with an enterprise app (doesn't need to go through app review) or an MDM profile (can touch some deeper system stuff sometimes), but given that they're currently in the teaser email capture phase, I doubt this will ever crystallize into a real iOS implementation.

I think they're just trying to get some message out, which is fair enough. FWIW, you can always manually set your iPhone to greyscale in system accessibility settings, which they do point out themselves.

[atareh]

The main point of this is definitely to start a "movement"

It's not about me or the app, it's just something that had a profound impact on my life and i'm trying to share that with everyone that might be struggling with this - that's why we include instructions to turn your phone gray natively. The app adds features that have kept some people from going gray even though they really want to (need phone for work and it's too much of a hassle to go menu hopping / navigation apps arent the best in grayscale etc).