Examine source code of Pageper

{
  "manifest_version": 2,
  "name": "Pageper",
  "version": "2.2",
  "description": "Minimalist and customizable startpage",
  "browser_action": {
    "default_popup": "index.html"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "chrome_settings_overrides": {
    "homepage": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{66b6cc4d-ea4a-41d8-92c6-ab82f66d0577}"
    }
  }
}