Back in the good old days when I used a Mac to manage and edit my photos I used Apple Aperture, Pixelmator, Photomatix and Perfect Photo Suite to edit my photos. When I got back home from a trip I had to sync all my photos to the computer, sort them out, edit and publish them. That took anywhere between hours to days.
Today, I can do all that on my iPhone; while waiting and even on the plane & in the train. No need to unpack a bulky and heavy notebook. Did I mention I love to travel light?
My iPhone photo editing toolbox contains 4 apps that enable me to do what I previously did on a computer.
I applied the same principle to choosing my favourite photo editing apps as I did for choosing the camera apps. Based on what kind of photo editing I did on the Mac, I looked for apps that allowed me to do the same thing on the iPhone; and today, you can do a lot of photo editing on your iPhone or even iPad and I'm not talking about filters here. So here's what I do:
adjusTments like BRIGHTNESS, CONTRAST, ETC.
That one is pretty easy. You don't need an app for that as you can do it directly in the iPhone photos app. Just tap the edit button when viewing a photo in the photos app and you can adjust a lot of things.
If you need a more sophisticated adjustments like curves, I turn to Adobe Lightroom Mobile or Enlight which is basically the swiss army knife of photo editing on the iPhone.
Advanced editing using Masks and Brushes
Sometimes I need to apply adjustments only to a part of an image to e.g. lighten only the shadows of the main subject. This is when an app that supports masks and brushes comes handy and my choice here is Enlight. For almost all adjustments, you can use brushes and masks to apply them to the entire photo or only a part of it.
Developing RAW (and even JPGs some time)
If you're on iOS10 and maybe already on an iPhone 7, you may have heard that you can shoot photos in RAW.
If you shoot RAW, you need to do that yourself. That's why an unprocessed (!) RAW photo can look worse than a automatically processed JPG of the same scene. So you need a RAW development app to make your RAW photos look rrrraaaawwww. On my Mac I used Apple Aperture for that. My choice on the iPhone is Adobe Lightroom Mobile.
Fix perspective distortions
I'm not an architecture photographer but still there are some occasions when I need to fix those things. Many apps I tried here had a major issue: They reduced the overall resolution of the final image. Not so SKRWT, which is the best app for fixing perspective distortions on the iPhone.
Based on what I need to do when I edit photos on the iPhone, here are the four apps I regularly use in no particular order.