need chrome extension developer

Hey , We are Ready with our new chrome extension now , But what I want is to do some tricks in it , we are giving this extension as a trail version to use and try so we want to give them option to perform only 5 task under trial , if they want to use more than 5 tasks they need to purchase the plugin membership ...so I want you to give this functionality in the plugin ...Demo video about chrome extension will be shared on. DM