I won't carry the weight of Hugh, but I'm a 5 figure author (with a number that that doesn't start with a 1), and I've been using the prototypes of this tool for months now while it was still secret and held among a closed group of authors.
This tool is indispensable. I can't even begin to explain how much so, but I'll try.
Ok, first, it's live. That means you run it in a tab and it's just ON. Any time you click on the tab, bam, your sales are there in live numbers. You can literally watch sales happen. That's pretty cool.
Second, it's secure. The creator of the tool is absolutely interested in total privacy. Data is stored locally, and you can see all the back end code that makes it work. That kind of transparency is huge to me.
Third, it's created by one of the most successful authors I know. This thing was built for personal use by a VERY high earning author and I've been fortunate to have access for so long. This is coded by someone who RELIES on this tool, and that means it's always worked, it gets relentlessly fixed when bugs pop up, and new features get added all the time. You are seeing the culmination of well over a year of effort here.
Fourth, this thing saves persistent data. That means as you run the tool, you'll save more than the 90 days of data Amazon shows you. That is HUGE.
FIFTH, this tool gives you the ability to quickly compare pennames and books, making it simple to figure out where to focus your energy. This tool replaced ALL my sales tracking and excel sheets on this subject.
Finally, it's a time saver. This tool means I don't have to keep going to kdp. I leave it in a browser window all day. I don't have to carefully track stats or do silly addition to figure out how much money I'm making. It takes the data Amazon gives you, and it displays it in the most elegant and beautiful way.
Put simply, this is incredible, and the man behind it is as brilliant as the tool he created.