Examine source code of Dailyreminders.org

{
  "theme": {
    "images": {
      "theme_frame": "Dailyreminder_hadder.jpg"
    },
    "colors": {
      "frame": "#9c9c9c",
      "tab_background_text": "#00ff37"
    }
  },
  "version": "2.0",
  "name": "Dailyreminders.org",
  "manifest_version": 2,
  "description": "Salamulikum, This is the Firefox theme for <a href=\"https://outgoing.prod.mozaws.net/v1/b087c2cf6d256ddfcdb4d8d1f780d7f24641a007449fdb809697c3aac89bb308/http%3A//dailyreminders.org/\" rel=\"nofollow\">http://dailyreminders.org/</a>\n\nuse it and have fun InshAllah"
}