Its not part of Mobility manager. Its a client for Mobile phones.
http://www.cisco.com/en/US/products/ps7271/products_qanda_item0900aecd805e69cf.shtml
http://www.cisco.com/en/US/products/ps7271/product_solution_overview0900aecd805e6a3c.html
There are two components in this solution. Cisco Unified Mobility Advantage that is a server that sits in your network to which mobile phones will connect. Mobile phones will run Cisco Unified Mobile communicator. The MObility advantage server will connect to the phone system, unity, meetingplace etc.
HTH
Sankar
PS: please remember to rate posts!
Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus