I'm sorry for the misunderstanding, but - the caption on the app is the filename.
So, for example, I name the file Grandpa Joe.jpg." Once you put the photo in the app/on the iPad, the caption reads "Grandpa Joe." No extra typing required.
What I meant by making captions is that you can turn captions on and then, I think, the app strips off the filename extension. So, it doesn't show the .jpg, .gif, etc parts.
The only extra bit, typing wise, that's needed is creating the folders.
Hope that makes more sense; sorry for the confusion.
Marilyn