GradeBook Pro is an app for the iPad that allows you to import a class list, take attendance, add projects and grades and export the material to your laptop as a .csv file.  The thing that makes GradeBook Pro stand out for me is the ability to take and connect pictures of your students with their names.  

I teach at a university with small classes and a ten week quarter.  I may have 50+ names to learn in a short period of time and names are not my strength.  However, with GradeBook Pro, I asked my students to allow me to take their pictures the first night and I was amazed at how quickly I was able to associate names and faces.  For the ones that didn't come quickly, I could easily refer to the attendance screen and see their names and faces.  In fact, I stopped passing around a sign in sheet.  I could mark students late or absent and indicate with a thumbs-up/down icon whether they had conferred with me about the absence/tardiness.

Another problem that GradeBook Pro solved for me was keeping track of posting of websites.  In my math methods class, after sharing websites that I find to be useful, I ask students to create an annotated Web Link in our Blackboard site.  While viewing the websites, I could easily mark each as completed and make brief comments that would help me when discussing their picked sites.

I was teaching a combined undergraduate/graduate class where assignments were different and I could easily exempt the undergrads from some of the assignments without creating a second grade sheet.

There are lots of ways to weight grades and even to email grades to students if you chose to do so.

What's even more impressive is the quick response you get when you question the developer, Eric Lombardo. He answered a question for me within hours of my sending it to him.  I've read that he works with people with special requirements as well.

For me, GradeBook Pro has been a lifesaver.  I feel like I get to know my students more quickly and they appreciate being called by name.  I have all my material organized for a class (and can add information from Assignments located in Blackboard, for instance).  You can back up and archive data.  Best $9.99 I've spent in a long time!