The best piece of software for simple cropping of images seems (to me) to be Shotwell Photo Viewer, especially as I find GIMP's cropping methods (AutoCropping & Zealous Cropping) incomprehensible.
I can start Shotwell Photo Viewer by right clicking the image file (in Nautilus). However, there are 2 Desktop Configuration Files for Shotwell & 1 for Shotwell Viewer, all loading Shotwell Photo Manager. I also don't see any shell script or executable for Shotwell Photo Viewer.
Can anybody supply a Desktop Configuration File for Shotwell Photo Viewer? Alternatively, can anybody point me to the shell script or executable for Shotwell Photo Viewer (in the Ubuntu Precise file system)?