Google Chorme Extension

I need someone to create a Google Chrome extension with simple functionality. when a person who has this extension installed and browse one of the sites registered in our endpoint, a message should appear. The query to our database will be done through an endepoint Rest, where you will get the urls and the information that should include in the message. It will be a differential if you deliver the extension already ready for Chorme and Firefox. The code must be delivered installed in the browser store, and the file with the commented source code should also be provided. Note: Endpoint and Database are ready, you will need to make a simple call to our Rest only using Jquery or Javascript. I will provide the documentation for this.