This one has an appeal that is much easier to convey than Omnifocus; Index Card is primarily visual. Its an electronic version of that fixture of edit rooms across the industry, a corkboard.
Index Card
Index Card is an iPad application that lets you make index cards, give them titles and short descriptions, make additional notes on the back of the card, color code the cards, and re-arrange them just by tapping a card and dragging it to a new location. It’s intuitive and looks great.