It’s remarkable to me how I do nearly all of my photo processing these days on iPad. Along that theme, the Pixelmator team just released a nice update with a focus on selecting objects.

Quick Selection Tool
Just swipe over an area to select it. This works better than you’d think. There’s a video below.

Magnetic Selection Tool
This is a long time Mac feature that now exists on iPad.
Learn more at the website or on the App Store.