Falcon is not your typical Twitter client. Rather, it is a widget designed to run completely on your home screen. While other Twitter widgets provide only a snippet of your timeline and essentially a shortcut to a full-functioning Android app, Falcon adds the Twitter functionality directly to your home screen so you don't have to boot anything else up.
To get started with Falcon, first add it to your home screen, just like you would any other widget. It's resizable, so you can experiment with both portrait and landscape orientations. Next, sign in and synchronize your tweets with the widget. Finally, tap the Falcon logo on the widget to choose a default Twitter app (if you have one installed). Your default app will then launch any time you tap the Falcon logo. Essentially, this creates a shortcut to a full Twitter app, in case you need to do things like edit your profile or add videos to your tweets -- things that Falcon itself cannot do.