Examine source code of Urligram

{
  "name": "urligram-browser-extension",
  "version": "1.0.2",
  "description": "Browser extension for www.urligram.com",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "img/logo_16.png",
      "32": "img/logo_32.png",
      "48": "img/logo_48.png",
      "128": "img/logo_128.png"
    }
  },
  "icons": {
    "16": "img/logo_16.png",
    "32": "img/logo_32.png",
    "48": "img/logo_48.png",
    "128": "img/logo_128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "*://*.urligram.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5b0cd376-6f5f-45c2-8512-8309214e88ea}"
    }
  }
}