Page-Turning PDF Feature

Not possible, and I would also recommend against it if it was. It just adds an additional layer of complexity to the file, which means more ways in which it can malfunction (which is exactly what's happening now with files that had this effect added to them using Flash in the past.)

In my opinion, there's no need to carry over affectations from an older technology to a new one. This might be something nice to have in a children's book, or when first introducing a new technology to a user-base that's not accustomed to it, but I don't see why an adult would need to have this kind of effect to make them "feel better" about reading a digital book nowadays.

You will never be able to add the page-turning effect to PDFs since this is not a PDF format feature.

This effect is a software feature, so it only depends on the software used.

For example you can use the page-turning effect in any PDF you like using ezPDF Reader PDF (Android only).

Please use this as an opportunity to reconsider. Do a survey to find out if your customers like this. Personally I hate it and will avoid companies who try to give me this "experience".