...why ridicule others for having some fun with it?
To be fair, the page-curl gesture was first seen in the third-party iPhone e-reader app "Classics".
Myst, assuming you play it on a touch screen, as prior art? (1:20 to 1:30ish)
"Right now I feel that I've got my feet on the ground as far as my head is concerned." -- Baseball pitcher Bo Belinsky