This, this is the exif app you're looking for. – EXIF Viewer by Fluntro Review

Excellent!!! 1)Has info (you decide which info it shows) on thumbnail view. 2)Also while you are using Apples own photo app there is a handy widget right there in 'share page' so you can see the photo's info. These two features are, (as far as I've seen) exclusive to this app.
Review by not_stickman on EXIF Viewer by Fluntro.