To use Mailtrack on another computer all you'd need to install the Mailtrack extension on that computer. To do so:
1) Open Chrome on the computer concerned, type https://mailtrack.io/en/ in the address bar then press enter.
2) Click on the green "install Mailtrack" button then click to add the Mailtrack extension to Chrome when prompted to do so.
3) Once you´ve done that, click on the "sign in with Google" button to complete the installation and activate Mailtrack on your email account.