Examine source code of Hivemark

{
  "manifest_version": 2,
  "name": "Hivemark - By Hive.one",
  "version": "0.7",
  "description": "User community and rank details from Hive.one inside Twitter app",
  "icons": {
    "32": "./assets/32.png",
    "48": "./assets/48.png",
    "256": "./assets/256.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "permissions": [
    "https://*.hive.one/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.twitter.com/*"
      ],
      "js": [
        "script.js"
      ],
      "css": [
        "styles/main.css"
      ]
    }
  ],
  "web_accessible_resources": [
    "script.js",
    "styles/main.css"
  ],
  "browser_action": {
    "default_icon": "./assets/32.png",
    "default_title": "Hivemark"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{98ea0015-082b-413a-acb5-82ccb45fa50e}"
    }
  }
}