Only talking about the guild_app product itself, it's totally self contained. you do not need the app_tools.xml or the images.
When you import the product, you'll have to go to the vbulletin options to set up the forum ID you want apps posted to , what user groups can post applications (generally you want registered members only to post apps, usergroup 2), etc.
Then you simply create a link some where that leads to
http://yoursite.com/newthread.php?do=apply (or
http://yoursite.com/forums/newthread.php?do=apply or whatever).
As i said above, it wasnt something i ever planned on releasing and i wrote it for the 3 main guild sites i administrate. another guild on the server wanted to know if they could use it for their site so i created this product. It wasnt written for the "beginer" type of vb user and i havent had time or a need to really go through the code and clean it up and really formalize options like they should be.
A good knowledge of usergroug and forum permissions is needed and some php skills to be able to find and tweak some settings yourself.
If you want help installing this or general vbulletin help, you can contact me through MSN, im usually on all of the time and i think you can get that info from my member info here.