Examine source code of CCaptioner

{
  "author": "Raymond Hill",
  "browser_action": {
    "default_icon": {
      "64": "icon-64.png"
    },
    "default_title": "CCaptioner",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "ccaptioner@raymondhill.net",
      "strict_min_version": "68.0"
    }
  },
  "description": "Assign a text track to a video element in a web page",
  "icons": {
    "64": "icon-64.png"
  },
  "manifest_version": 2,
  "name": "CCaptioner",
  "permissions": [
    "activeTab",
    "<all_urls>"
  ],
  "version": "1.1.0"
}