With the enhancements to Lync Web App, there is no Lync Attendee
for 2013. In order to connect Android, iPhone/iPad devices you will need to
install Lync mobile client on Lync mobile device.
Use client version policies to specify the versions of clients
that are supported in your environment. You create or modify
client version policies from Lync Server 2013 Control Panel or Lync
Server 2013 Management Shell.