Read the description carefully!

The app developer truthfully states that this app changes the date displayed inside Photos. That is absolutely true, and it works as advertised. (But you don’t need this app in Photos, because Apple built the exact same functionality into Photos.)

This app DOES NOT CHANGE THE CREATION DATE OUTSIDE OF THE PHOTOS APP.

This product would be much more useful it it actually/really/truly changed the date of photos that are not in iPhoto or Photos.

ToddRuel about Image Redate