Just like the name stats, it talks about the activities on your steemit profile, as related to incoming votes, recent activity on your feed, division of steem dollar and steem power from a post payout before it due time, and so much more. Personally, the best part I like about this page, it is ability to divide a post payout into steem dollar and steem power saving you the time to calculate your expected payout. Although, there might be mistake with the calculation as nothing is perfect.
This is cool for the steemstats app