Google Photo just annonced that thier free service is now gone. There is now room for a new player and since Dropbox is already one of the top used storages services for photos this would be an amazing fit. What I'm suggesting is a stand alone Photo app that gives users the posibility to brows view their Dropbox photos in one place. A few suggestions of features are:
* Automatic face recognition and categorization
* Search (places, objects, etc.)
* Map with all photos
* "Remember this day in photos"
Personally I don't think it needs editing features to start with, but maybe down the line!