I found the website:
iPhone cases
I've never heard of them before, but I can give you some feedback. I have just a regular black leather flip case for my iphone. Done the bottom of the case where on the picture on that website (red and green cases) there is a lot of little holes (6). That will be a problem.
With leather cases if you want to use the phone as an ipod and have the headphones on, you need to flip the phone 180 degrees, putting it into the case upsidedown. So those 6 little holes, should instead be 1 round hole for an earbud jack.