BlueTicks for Gmail

BlueTicks for Gmail adds WhatsApp style read ticks to Gmail. One tick means your message was sent. Two blue ticks mean it was opened. The ticks appear directly in your Sent list, so you can see the state of every message at a glance instead of opening a dashboard or switching to another tab.

It runs in Chrome and Firefox, on personal Gmail and on Google Workspace, and it handles several accounts in the same browser.

The free tier covers 30 tracked emails a month. Beyond that it costs 4 dollars a year.

I build it myself, and everything it needs from your browser is declared in the extension package for anyone who wants to read it.