Facebook has announced new features for several of its mobile apps. The Android client has been updated to support the Groups feature recently added to the website, allowing contacts to be grouped based on common interests, and also supports the Places location-based service. The iPhone app also now includes Groups support, a new composer to make checking in and posting photos faster and clearer, and supports the recently-announced Deals mobile commerce service. Both apps now also support single sign-on, so the Facebook user ID can be used to access multiple apps and services.