Previously, you can only hold certain amount of apps in one folder. I think it’s maximum 9 or 12 apps allowed to be in one folder. Not any more in iOS 7. Folders now are page-able, allowing them to hold a huge number of apps. I haven’t tried putting more than 2 pages of apps in one folder but you can always try to keep throwing apps in to see how many pages of apps one folder can actually hold.