Examine source code of send-to-spillo

{
  "description": "Send to Spillo Extension",
  "manifest_version": 2,
  "name": "send-to-spillo",
  "version": "1.4",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/logo.svg",
      "32": "icons/logo.svg",
      "64": "icons/logo.svg",
      "96": "icons/logo.svg"
    },
    "default_title": "Save with Spillo"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6a869f54-912c-4942-8f5d-7a1ece5b4848}"
    }
  }
}