Once you choose a server, you can search for the anime you want and start watching any episode immediately. Stream them, or download them to your device so you can watch them later even without an Internet connection.
You do need an external player in order to watch the episodes, though. The built-in image gallery in Android is enough to stream them, but you can also use VLC or MX Player.
AnimeDLR is a great app for anime fans. It lets you watch the latest episodes of your favorite series, directly on your Android. The interface is nice and elegant, and lets you save your favorite series and manage the episodes you download.
Requires Android 4.0 or higher