"The GIMP for those who come from Adobe Photoshop for Windows".
It works on Ubuntu, Fedora, Debian, their derivates and all other major Linux distributions.
PhotoGIMP is originally a GIMP layout modification to look like Adobe Photoshop made by Dionathan Simione from Diolinux. A lot of people only uses GIMP with the modification. This patch on GIMP helps who want to use the original theme by embedding it on GIMP.
Note: I am not the developer I did not make this appimage either, just pointing to a link of one.
Appimage can be updated using appimageupdate, appimage on this site should always point to the latest release.