Examine source code of Night Mode Toggle

{
  "name": "Night Mode Toggle",
  "version": "1.0.2resigned1",
  "description": "Turn night mode in any page, to browse comfortably during the night",
  "author": "Frankline Sable",
  "homepage_url": "https://github.com/Frankline-Sable",
  "icons": {
    "48": "icons/night_48px.png",
    "96": "icons/night_96px.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/day.png",
    "default_title": "Night MD",
    "default_popup": "popup/change_mode.html"
  },
  "web_accessible_resources": [
    "popup/images/moon_smile.png",
    "popup/fonts/Helvetica-Normal.ttf"
  ],
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{bbdb3b48-97c5-4dbd-a101-020d0476260d}"
    }
  }
}