...
- Login and registration are not implemented
- All feed items are canned; there is currently no way to pull items from Twitter, Facebook, etc.
- The "Share" and "Save" buttons are stubs (these two actions are not directly related to the three essential tasks)
- Marking items as read has been left out (not one of the three essential tasks, and anyway, you'd quickly exhaust the list since it's canned data)
- No persistence - hitting refresh gives you a completely clean slate.