Here's a tool for viewing your monthly sales of each product per month.
Just like in the Easy Updates mod, You'll need to replace YOUR_API_KEY with your own google API Key, as well as use the tablesorter.js plugin.
Select the year and month you would like a report from - by default It will be the current month.
Keep in mind that the % change from the last month is only meaningful if you are looking at a month that has already completed!