You have two problems: First, you evidently did not add "cupertinostreamingpacketizer" to the /conf/videochat/Application.xml /Streams /LivestreamPacketizers.
And the default video and audio codecs using Flash are not supported. With recent Flash versions you can use H.264 video and Speex audio along with the Wowza Transcoder to publish in Flash and playback HLS streams in iOS devices. It is not really suitable to chat, but it will work. Take a look at this article.