Is stuffs plural from stuff?

0Hi,02br
00Is there any difference between the words stuff and stuffs? I don't know if stuff is countable or not, but stuffs should be plural, shouldn't it? However, I searched Google to check about it and I've found that many pages have something as "Free stuff" or "Funny stuff" - it can't be that they offer only one thing on their page, but I've found "Cool stuffs" as well and I'm confused now.02br
00Thanks in advance.02br
00p.s. Does the usage of present perfect/simple past fit in the above paragraph? 0-