Examine source code of Screenshot Tool Plus

{
  "manifest_version": 2,
  "name": "Screenshot Tool Plus",
  "version": "1.0",
  "description": "Capture full page or visible screenshots easily.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Screenshot Tool Plus",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "follow.c.o.ws1.41@gmail.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "tabs",
    "<all_urls>"
  ]
}