PhotoExif is an app that lets you add EXIF data to photos shot with a film camera. You can dial in aperture, shutter speed, focus distance and focal length, along with notes about your photo, and when you get the photos back, freshly scanned from the lab, you can add the info to the digital images.
Back when I was studying photography in school, I used to carry a notebook. This was back in the days of film, before SLRS even had autofocus, and the notebook was for writing down the camera settings for each shot: aperture, shutter speed and so on.
As you can imagine, I didn’t manage to keep to this regime very often. Instead, I learned to look for clues in the pictures which would tell me the details: blurred leaves on a tree? Shutter speed of under 1/125th sec. Front-to-back focus? Aperture of ƒ11 or ƒ16.
PhotoExif, on the other hand, takes out the guesswork, although you do have to put in a little more effort when shooting. And the app adds in some features I never even dreamed of back in my school days: it’ll capture the GPS co-ordinates of your pictures (as long as you input the data when you actually snap the picture).
Then, when you’re back at the computer, you load up the (free) Mac companion app and so the tagging right there with your iPhone.
If I was shooting film, though, I’d probably just skip this and snap two extra pictures with my iPhone: one of the scene in front of me (as a reminder) and one of the top of the camera. From this second shot I could see all the available settings: aperture, shutter speed, film speed, focal length and distance. Then I could go home, have children, wait for them to grow up a little and set them to some serious data entry, tagging my film pictures based on my iPhone ones. Foolproof.