Thanks for posting your question, Tim.
If you are joining one of the live webcasts that are offered by GCSAA education (or an Industry partner from our web site) the software used is GoToWebinar from Citrix. They have a free app you can use to join on your iPad or phone. You can read more details about use on their web site here:
http://support.citrixonline.com/GoToMeeting/ and search for iPad
I know there have been a couple of members use the app to attend our Today's Turf is…. Series and it has worked well, overall.
The webcasts that we have recorded in the On Demand library have been created over time and have been done with various software. We started using GoToWebinar in Sept. of 2012 so you should be able to open those recordings using Mac products. Before that we used a Microsoft product which didn't work well with anything "i".
Please feel free to contact me with any questions or if you need further tech support. Lisa Wick