Kindle Manage Your Content and Devices Page has New Features
There is a new column that lists the number of devices that each books is downloaded to. If you click on the number a popup will show exactly which Kindle devices and apps the book has been downloaded to, and when you click the device it will show a list of all the content on that specific device and let you remove it. Amazon has also revised the layout of the devices page. You can select each individual device or app that you have registered to your Amazon account, and if you click on it you can view a page with more information about the device.