Free Email Tracking for Gmail - Mailalert

Mail Tracking without any branding and for free! Easily add double check marks (✓✓) to your Gmail.
Premium users can view and search full source code, and see the source code differences between two versions.
manifest.json
{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "__MSG_storeExtName__",
  "short_name": "__MSG_extName__",
  "version": "1.0.7",
  "version_name": "1.0",
  "manifest_version": 2,
  "description": "__MSG_extDesc__",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "page_action": {
    "default_icon": {
      "16": "icons/icon-16-grey.png",
      "32": "icons/icon-32-grey.png",
      "48": "icons/icon-48-grey.png",
      "128": "icons/icon-128-grey.png"
    },
    "default_title": "__MSG_extName__",
    "default_popup": "popup_noop.html"
  },
  "background": {
    "persistent": true,
    "scripts": [
      "vendor/raven.js",
      "utils.js",
      "config.js",
      "vendor/utf8.js",
      "vendor/quoted-printable.js",
      "background_scripts/MailParser.js",
      "background_scripts/utils.js",
      "background_scripts/gapi_client.js",
      "background_scripts/messages.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "css": [
        "styles/injected.css",
        "styles/mdl-button.css",
        "styles/mdl-switch.css",
        "styles/firstRun.css"
      ],
      "js": [
        "vendor/raven.js",
        "vendor/chrono.js",
        "vendor/inboxsdk.js",
        "vendor/kefir.js",
        "vendor/moment-with-locales.js",
        "vendor/mdl-button+switch.js",
        "utils.js",
        "config.js",
        "content_scripts/i18n.js",
        "content_scripts/mdl_utils.js",
        "content_scripts/utils.js",
        "content_scripts/firstRun.js",
        "content_scripts/sdk_utils.js",
        "content_scripts/notifications.js",
        "content_scripts/websocket.js",
        "content_scripts/email.js",
        "content_scripts/DateParser.js",
        "content_scripts/content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "identity",
    "identity.email",
    "webRequest",
    "webRequestBlocking",
    "https://mail.google.com/*",
    "*://*.googleusercontent.com/*",
    "storage"
  ],
  "optional_permissions": [
    "tabs",
    "notifications"
  ],
  "web_accessible_resources": [
    "web_accessible_resources/*"
  ],
  "oauth2": {
    "client_id": "991711836099-9op7b2fgm2qb0cfpqqgf04ocl5c2une3.apps.googleusercontent.com",
    "scopes": [
      "https://www.googleapis.com/auth/gmail.modify",
      "https://www.googleapis.com/auth/gmail.insert"
    ]
  },
  "content_security_policy": "object-src 'none'; script-src 'self' 'unsafe-eval'; style-src https://code.getmdl.io; connect-src https://www.googleapis.com https://accounts.google.com https://track.mailalert.io https://sentry.imper.cz; img-src https://track.mailalert.io https://*.googleusercontent.com/ cid: https://*.google.com; report-uri https://sentry.imper.cz/api/50/csp-report/?sentry_key=106a2505172741cf8b3426caf2c9296b&sentry_release=1.0.7"
}