FYI, I looked at your EPUB in iBooks, and at least from the perspective of someone who doesn't speak Hebrew, it appears to be rendering it correctly. The pages turn the opposite direction, and the punctuation is all down the left end of every sentence.
With that said, it might also be worth adding:
in your CSS. With that said, it seems likely that GitdenReader just doesn't support turning pages in the opposite direction. Is the text at least rendered correctly?