New GIMP AppImage version available in the community software page.
The main improvement in this version is that the start-up time has been greatly reduced by avoiding the re-scanning of plugins at each execution. Now the AppImage launches practically as fast as the standard GIMP.
If you are interested in the full story behind this improvement, you can read it here and here. A BIG THANK YOU to @probono for discussing the issue with the GIMP developers and getting a fix in a very short time!
The size of the AppImage package has also been reduced from 130MB to 90MB by stripping the debugging symbols from the GIMP code and removing some unnecessary executables.