Where dd downloaded pictures go on your iPhone?

I downloaded the app called "Wallpapers HD for iPhone, iPod and iPad" and when i started it asked if i wanted to let the app access my photos. I unknowingly clicked no, and then downloaded a bunch of pictures. The pictures don't show up in the "photos" part of the phone and i can't find them anywhere. Also, I tried to change the settings so that the app is able to access my photos, but i can't find that option anywhere. Does anyone know where the pictures are or how to fix this?

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Delete the app and install it again and allow the photos this time. See what happens and just try to download a photo and check the camera roll. Oh and try the app photo buzz (Not HD/paid version), never had a problem and ignore the Asian girls