Examine source code of Screen Shader v2

{
  "manifest_version": 2,
  "name": "Screen Shader",
  "version": "1.0",
  "description": "Adjust your screen's color temperature for a more comfortable browsing experience.",
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3e05ecba-acdb-45a8-a253-0255bd599f7f}"
    }
  }
}