To use Mailtrack in Chrome's incognito mode:
1) Click the three dots at the top right of Chrome and go to Extensions > Manage Extensions. You can also type chrome://extensions in the address bar and press Enter.
2) Find Mailtrack® – Email Tracker for Gmail in your list of extensions and click Details.
3) Turn on Allow in Incognito.
4) Click the three dots at the top right of Chrome and select New Incognito window.
5) Sign in to Gmail in the incognito window you've opened.