I'm very surprised that this isn't already a feature because almost every editing app has it, even photoshop express. I want to be able to correct the hue/saturation on all the colors in the picture. Not just the master. This is one of the editing I do mostly on my pictures. I give you a screenshot from the computer version and one from ps express.
Here you can see this is missing on photoshop for iPad.
Please fix this as son as possible