Use Case Diagram

I have done use case diagrams for my application to show the user experience and the key features of my app.

click on the image below to view the larger version. 

or click on the link below to view the PDF file: 
https://dl.dropbox.com/u/23409639/ucd.pdf

Brief description of flow diagram:
1. user logs in to accounts (Instagram/pinterest/tumblr, or all of them)
2. user chooses photo sharing sites to view photos
3. user shares photo and chooses the destination to share the photo.
4. user go back to photos feed and view the photos
5. user chooses and collect the photo they like either from instagram, pinterest, tumblr (as long as they have logged in)
6. user add label and save the photo to their collection
7. after collecting, user can choose to go back to view photos, to share photos or continue collecting photos.

this flow diagram basically shows the user experience where they can view, share and collect photo.