Yes, all of Teamleader's Chrome Extension functionalities are compatible with the new design.
Earlier this year, Google launched a new version of Gmail with some new features. It was rolled out to G Suite users starting July 2018 and will be rolled out for all users in the beginning of October. From then on, you won't be able to switch back to the classic Gmail version.
In terms of functionalities, nothing was changed. Tracking new emails you compose is still possible:
The tracking box for incoming emails is also up and running:
As mentioned, in October the new Gmail design will be live for every user. Make sure you have updated to both the new Gmail design and the new Teamleader Gmail plug-in by then, as the former version does not function in the new user interface.
If you haven’t switched to the new Gmail design, you can do so by clicking the cog wheel in the top right-hand corner of your Gmail account:
If you are not sure which version of Teamleader’s Chrome extension you are using at this moment, click the link to the Chrome Web Store to find out.
Version 2.1.15 or later is compatible with the new design: