Last term I have been teaching image editing tools and techniques to my year 8 students (12-13 years old). We have used GIMP (similar to the well-known Photoshop). I am very happy with the outcome and students had fun learning :D
Below you can find a small showcase of the work they have done.
Year 8A https://padlet.com/lionel_ta/vw700bcaa00v
Year 8J https://padlet.com/lionel_ta/mcvt7gseg98j
Year 8T https://padlet.com/lionel_ta/56fpn0c5x8rz