Is there a signature-taking attendance app for iOS?
I've used FormEntry for Mac to do this at team meetings. I push out the form to an iPad, and send the completed signed roster to a PDF when the meeting is completed. Caveat: you do need the Mac to design the form, and then you need to push the form to the iPad when completed. This might not be the most cost effective solution, but it works nicely for this and other applications.