I just discovered wallch and I installed it on my Ubuntu 12.04. I really like it. Now, I would like to use the "change wallpaper in random time (2-20) minutes" option on startup.
I enable the "startup option" in the preferences menu, to allow Wallch runs every time I do login, and a Wallch item is automatically added to my Startup Application Preferences. Looking at it, it runs the program with the option --constant, instead of "random".
It doesn't seem to exist any option on the command line to start the program in the "random time" mode. Is there a way?