Examine source code of Add HTTPS

{
  "manifest_version": 2,
  "name": "Add HTTPS",
  "version": "1.2resigned1",
  "description": "Toggle http(s) on current tab url with a single click",
  "homepage_url": "https://github.com/sanspace/add-https",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "page_action": {
    "default_icon": "icons/padlock_red.svg",
    "browser_style": true
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@add-https"
    }
  }
}