ViewExif is an iOS extension which allows you to view exif metadata of photos. Exif metadata is data about the photo like dimensions, taken date, ISO speed, F number, exposure time, focal length and more. It will add a button to your share sheet in not only the Photos app but any app that displays photos. Since Apple does not give up this information directly in the Photos app, this is a handy extension to have.
Works great though I had problems with the Twitter referral link.