Android: The folks at CyanogenMod have announced a new photo management app beta called GalleryNext that will probably be part of upcoming CyanogenMod releases. If you're happy to join a a beta, you can get it now.
The app pulls together your photos from your phone as well as various cloud sources including Picasa, Flickr, Facebook and Dropbox. It can also sort your photos by album or "moments", which seems to group them together by date. Other than sorting options, the app is pretty spartan right now, but it's likely more features will be added later.