Add meta information to photos?
There are a couple of apps in the Playstore which permit you to view/Edit EXIF data:


Photo Image Editor - Photoshop (free) says it can View, edit, or delete EXIF data
Same promised by Photo Editor
Exif Editor and Viewer (paid) promises to remove, modify, and add individual or multiple EXIF tags
Pixelgarde even states: Edit exif metadata for several photos as a batch, or just individual photos


There are probably many more, so I just picked two of the more promising examples.