Examine source code of Flash Telecom click2call

{
  "manifest_version": 2,
  "name": "Flash Telecom click2call",
  "version": "1.0",
  "description": "",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "contextMenus",
    "storage",
    "*://*.panel.fmeuropa.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Flash Telecom click2call",
    "default_icon": "icons/icon.png",
    "default_popup": "popup/content.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6db47d78-3f56-4c0f-aaa5-d5a35b0fa100}"
    }
  }
}