We have an iPad/iPhone app available at the Apple iTunes store. And the Android app is available from http://www.rhubcom.com/v5/support.html
and a new version should be available from the Google Play store in one or two months. These apps allow you to control remote PCs and Macs. And you can attend meetings, use your built-in mic and speakers, share your webcam and see other's webcams. These apps allow you to host meetings, which is handy if you are on the road and need to use the free audio conferencing service. However, these apps do not allow you share the screen of your iPad/iPhone/Android with others.
We do not have any short-term plans for developing a Windows Phone app. TurboMeeting does run on MS Surface tablets and other Windows tablets.