https://www.cnet.com/news/this-iphone-xr-xs-app-lets-you-blur-the-background-and-foreground-in-portrait-mode-photos/

My favorite feature, for instance, is the app's ability to adjust both background and foreground bokeh like an actual lens and camera. Portrait mode photos can be shown in a side view, revealing contour map-like slices that represent depth. Sliders let me adjust which parts of the background and foreground get blurred.

Focos lets me change the quality of the blur, too. For example, I can make it more creamy or more swirly in appearance. I can also add effects that make out-of-focus areas take on different shapes like stars, triangles and hearts. The OnePlus 6 had a similar feature in its default camera app, but it didn't work as elegantly.