Facebook users include just about everyone you know and anyone you might ever imagine knowing, but through that tool you're more likely to find photos of their kids and bulletins of what they had for dinner, rather than assistance finding a job. If you want to network for business, use LinkedIn. Period.
The LinkedIn app for Android brings the business network service to your phone effectively and efficiently. The user experience with the app works much better than trying to browse the website over your phone's browser. With a few taps, it's easy to tour through your connections, read people's profiles, and invite them to "connect."
Helpful icons across the top of the screen let you share an update (with everyone or just your connections), check your LinkedIn inbox, or search the whole service. The home screen of the app provides access to updates from all your connections, pending invitations from others, a list of "people you may know" and another path to your LinkedIn email messages. Your own profile appears at the bottom of the main screen so you can quickly see how you appear to others in the network.
Is it perfect? No. The website provides company information that would have been useful to include in the mobile app. But LinkedIn says it will continue to improve upon and add features to this useful app.