Games : Why is minecraft forge not working for zip files?

I got minecraft forge latest on my computer gone to %appdata% got my mod in .minecraft/mods launch minecraft and... to my surprise it said only 3 mods loaded which are the ones that come in for the forge. This only works for jar files like MrCrayfish's furniture mod and iChun Util and stuff like that. But nothng says PortalGun mod by iChun (The mod that I tried to install) The zipped compressed file. So why this it do this? I tried every other mod but nothing worked. Please help