Examine source code of Reverse Image Search

{
  "manifest_version": 2,
  "name": "Reverse Image Search",
  "description": "Search similar images in the WEB from context menu",
  "version": "1.1",
  "permissions": [
    "contextMenus"
  ],
  "applications": {
    "gecko": {
      "id": "yromkaqfsd@gmail.com"
    }
  },
  "background": {
    "scripts": [
      "search.js"
    ]
  },
  "icons": {
    "128": "icon128.png"
  }
}