Each new version of iOS users come across errors and find ways to use them for their own purposes. Some bugs remain in the system for several releases. IOS 9 is no exception. In iOS 8 users have discovered a bug (or feature?) with folders, which successfully migrated into the ninth edition of OSes Apple.
The peculiarity of springboard in iOS 9 allows using simple manipulations add folders into folders. How this can be done deftly demonstrated great under the name Videosdebarraquito.
First of all you should place on one page spingboard two folders – one of which needs to be put in another. They should be spread for some distance: one folder you can move to the top right corner, the second one in the lower left. Then switch to move/delete the icons and take a finger one of the folders. Now if you try to open another folder while holding, it opens. After this will let go of the finger that one folder was inside another. Thus you can add folders within folders an unlimited number of times.
To return the icons on your home screen, just move the icons in the navigation mode and remove the folder as any other app. Reboot iPhone and iPad does not restore the icons.