Examine source code of Sourcer

{
  "name": "Sourcer",
  "description": "The one tool for all news insight.",
  "version": "1.4.5",
  "manifest_version": 2,
  "icons": {
    "16": "./logo16.png",
    "32": "./logo32.png",
    "48": "./logo48.png",
    "72": "./logo72.png",
    "96": "./logo96.png",
    "128": "./logo128.png",
    "144": "./logo144.png",
    "192": "./logo192.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "./main.js"
      ],
      "css": [
        "/main.css"
      ]
    }
  ],
  "browser_action": {
    "default_title": "Sourcer",
    "default_icon": "./logo.png",
    "default_popup": "./popup.html"
  },
  "background": {
    "scripts": [
      "./background/main.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "*://getsourcer.com/*",
    "*://api.getsourcer.com/*",
    "webRequest",
    "clipboardWrite"
  ],
  "web_accessible_resources": [
    "*.png",
    "*.gif"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "browser-extension@getsourcer.com",
      "strict_min_version": "42.0"
    }
  }
}