Grumbleduke was showing you a preview image. It just gives you an idea of what the cover will look like. We dont show the flat image on the forums in full size becasue it would be far too large to see the entire cover. You can get the downloadable full size image when we upload it to the site under its own section. Problem is at this time we are unable to add any covers to the site due to a security issue.
I was thinking it would be somewhere else, like Flicker, Photobucket, or etc.
If i were you i would just go to Adobe's website i download a free 30-day trial of photoshop for you to use. 
I'll totally be doing this during Summer Break. I discovered your amazing site and the idea of making covers at the END of summer break, so i haven't had time to commit..i'm on Christmas Break, so i have a little time to play now, PLUS i'm getting my 100 Univ.Game.Cases tomorrow! first time ever having them (i've been mostly working on DVD cases and Sega Genesis cases until now).
When i FIRST discovered your site, i was at the Beach, and i checked the Office Max there, and was shocked at the price for PhotoShop.
I just googled some stuff about PhotoFiltre, it doesn't even support layers.
If I were you, for a free program, I'd just use GIMP. As far as freeware image editing goes it's about the best you can do.
Layers? never heard of them(i'm a noob)...but i love learning this! I plan to do this all summer(even commit to buying a Laser Printer)
GIMP? I'll have to check-it out. I'm either learning that PhotoFiltre is too small, or i just haven't figured it out. You guys are awesome! How long did it take you to learn and get up to par?