I have been using the Lync 2010 client on my iPad and iPhone quite a lot for the last 6 months, but got frustrated by the limited functionality. Travelling on the train today, I thought I would try again and see if anything had changed. When I logged in on my iPad the Lync client promoted me to download and install the Lync 2013 client, so off to the App Store I went and downloaded the client.
I was very happy to find following the installation, and very quick configuration steps (providing my mobile number, and asking which services you want to use you mobile data plan for) that most, if not all the functionality which is available in the desktop client has been enabled, so I can now make Lync to Lync calls from my device, view content provided during Lync meetings.
We are currently using Office 365 for our Lync deployment, but as I understand it, to enable the use of the Lync 2013 client with a Lync 2010 server installation the February 2013 update needs to be applied to your internal deployment.