I use TrackerBox and have been quite pleased with it. It puts KDP royalty reports into very sensible order, then you can play with sales figures across your titles during whatever time periods you choose right within the tool or download the data into a spreadsheet for even more charting fun. It can handle Apple, BN and other vendors too (even those that report through Smashwords), though the last update of the tool chokes for me on Smashwords. Since I have only one book there, I can deal with it manually until I figure out the issue (which may well just be on my side). KDP is very smooth, though.
If you have several books and/or authors, I think it's definitely worth the (tax-deductible) cost.
http://www.storyboxsoftware.com/
If you have several books and/or authors, I think it's definitely worth the (tax-deductible) cost.
http://www.storyboxsoftware.com/