Examine source code of Pocket Easy Popup

{
  "manifest_version": 2,
  "name": "Pocket Popup",
  "version": "0.2",
  "description": "Show the Pocket page on a pop-up to easy access",
  "icons": {
    "48": "icons/pocket.png"
  },
  "browser_action": {
    "default_icon": "icons/pocket.png",
    "default_title": "Pocket Popup",
    "default_popup": "pocket_popup.html"
  }
}