Examine source code of Soothe

{
  "manifest_version": 2,
  "name": "Soothe",
  "version": "1.0",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "browser_action": {
    "default_icon": "favicon.ico",
    "default_title": "Soothe"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e3712d4-0078-4aa8-a57e-8a35f300deff}"
    }
  }
}