With one image on the screen you can swipe left to go the next one, or swipe right to go back. Buttons across the bottom let you mark a photo as a favorite, share it on social-networking services, make a comment, or get more information.
Flickr doesn't have as many filters and extras as some of the apps out there, but it has a pretty good range of ways to enhance your images before you upload.
Hit the information button in the bottom right of a photo to see a slide-up information window with photographer-written descriptions and time and location of the shot, or view groups and sets to continue browsing.