Accessing Chalk from an iPad or other mobile device is, indeed, possible. That’s the good news! The bad news is that there is a small charge for the app – $1.99 for unlimited usage for a year and $5.99 for unlimited use forever. Up until September 2012, Blackboard provided the Blackboard Mobile Learn app for free; however they have changed their business model. The app can be downloaded for free – the charge kicks in when you try to open it. See https://answers.uchicago.edu/page.php?id=22208 for more information.
As an alternative, you can download your course documents on your laptop and move them to your iPad using a utility like DropBox. (On the iPad, this would save you from the, IMHO, irritating font used by Blackboard!)