Examine source code of Resize Window & Viewport

{
  "version": "1.0.7resigned1",
  "name": "Resize Window & Viewport",
  "author": "Moris Papasmadov",
  "description": "Resize browser window & viewport to common screen widths",
  "homepage_url": "https://addons.mozilla.org/en-US/firefox/addon/resize-window-viewport/",
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "morisdov@windowviewportresizer",
      "strict_min_version": "48.0"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "browser_style": true,
    "default_title": "Resize Window & Viewport",
    "default_popup": "resizer.html",
    "default_icon": {
      "19": "icons/window19.png",
      "38": "icons/window38.png"
    }
  },
  "icons": {
    "48": "icons/window48.png",
    "96": "icons/window96.png"
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}