I download and test it with my iphone and my lync lab environment and works still fine!
You can find Xync™ as an example in the Apple App Store for 15,99€, but I think its worth every cent!
After configuring the client with OCSR2 or Lync Server without Autodiscover it always crashs when starting the app. Reinstalling the app and configure again with the lync Account and every think works fine again.
It seems like the problems persist only if I don´t use autodiscover for the configuaration
Another Point is, when I using the 3G Network for the connection Audio and Video doesn´t work :-/