POWr is a cloud-based system of plugins that work on almost any website. A POWr plugin will 'recognize' you as their owner based on your account details. So you can edit your plugins, but no one else can.
You also need an account to view data for certain plugins like POWr Form Builder.
Finally, POWr lets you edit and manage your plugins on any website, from any computer, as long as you log into your POWr.io account.
(Note: You do not need a POWr Account to use POWr through the Wix App Market)