Tap on your photos menu
Find the photo you would like to hide and tap on the share icon in the bottom left hand corner.
Scroll down until you find the "hide" option.
Select "Hide photo"
If you would like to access your hidden photos, select your albums menu at the Botton of your camera roll.
Scroll down until you find Hidden menu under Utilities.
This will show you all the hidden photos in your "hidden album".