To a certain degree, Facebook is made for mobile usage. Being able to send status updates, upload photos, and see what your friends are doing is great when you're out and about. But the Android Facebook app itself can turn aggravating.
Outside of basic status updates, the app itself is a shadow of using the full Facebook interface in a browser. Navigating Facebook is not the easiest thing in the app. Also, chat is poorly implemented, and uploading images can be tedious.