[Uncorrelated]

I'm sorry for neglecting to respond until now. The app was called Portrait Effects Studio and later Portrait Effects Playground; I took it down because it didn't meet my quality standards. I don't have any public videos anymore, but it supported background replacement and filters like duotone, outline, difference-of-Gaussians, etc., all applied based on depth or the portrait effects matte. I can send you a TestFlight link if you're curious.

I looked at your apps, and it turns out I'm already familiar with some, like 65x24. I had to laugh -- internally, anyway -- at the unfortunate one-star review you received on Matte Viewer from a user that didn't appear to understand the purpose of the app.

One that really surprised me was Trichromy, because I independently came up with and prototyped the same concept! And, even more surprisingly, there's at least one other such app on the App Store. And I thought I was so creative coming up with the idea. I tried Trichromy; it's quite elegant, and fast.

Actually, I feel we have a similar spirit in terms of our approach to creative photography, though your development skills apparently surpass mine. I'm impressed by the polish on your websites, too. Cheers.