Looks interesting, but it seems to be a landing page to gauge interest with no app available yet.
Edit: To be clear, I set my phone to grayscale a little while ago, so I'm aware that's built in to iOS. I think the additional features that this app idea is proposing on top of that feature are great, but it seems like the app does not yet exist (and perhaps not possible with iOS's limitations).
Edit: To be clear, I set my phone to grayscale a little while ago, so I'm aware that's built in to iOS. I think the additional features that this app idea is proposing on top of that feature are great, but it seems like the app does not yet exist (and perhaps not possible with iOS's limitations).