Having used a large number of keyword rank tracking tools available (probably all of the known brands, and more!), I can honestly say AccuRanker provides a number of great features, in a slick and well-developed product.
Most importantly to many, it manages to achieve this without the need to spend a high monthly subscription. It easily matches the features of the other leading keyword rank trackers that I have used, and in some cases betters them. Our team have found great use for it and it is integrated with our monthly client reporting.