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.
That said, Falcon does have all of Twitter's basic functions built in, which is more than I can say for any other Twitter widget I've seen. It offers a resizable stream that can be toggled between your Twitter timeline and your mentions. There's a refresh button and a jump-to-top command (single tap on the toolbar). And of course, you can compose tweets -- complete with photos and location tags -- right from the widget. If you want to mention another user in your tweet, it helps that Falcon autocompletes based on users you're following.
As you read through your stream, you can tap any tweet to expand it into a pop-out window. And what's nice is that any rich content -- links, images, and videos -- will show up as a preview in the window as well. The pop-out even shows you replies from other users, and lets you compose your own replies, retweet, favorite, or reshare to other apps. This is, by far, the most functionality I've seen in any Twitter widget. Overall, it's perfect for quickly consuming content without having to boot up a full-blown Twitter client, browser, or any other app.