"iPad is a versatile device only when coupled with the "right" apps. To tap into the full potential of iPad and to leverage it for your professional learning purposes, you should definitely have certain apps installed on it. Here is a list of some important apps to start with. Of course the selection is based on my personal experience with app reviewing. I have reviewed hundreds of apps in the last couple of years and the ones below, I believe, are the best in the area of professional development:"
Via John Evans