Camera: GrapheneOS’s camera app. Have been my camera of choice ever since I’ve discovered it. Never had an issue, offers all the basic features you would expect from a camera
Meta: just making sure that anyone that reads this comment is aware of the existence of Obtainium!
Obtainium allows you to install and update Apps directly from their releases pages, and receive notifications when new releases are made available.
It depends on what you want to edit :P if you just need the basics (sketching, filetrs, resizing, cropping, converting, combining, etc), try ImageToolbox