For Zoho Books, it would be immensely helpful as a user reminder if there was a dot added to the favicon to reflect the timer state. See the attached image for an example of the various states. This would provide users of the timer module a visual reminder, when the Zohobooks window is not active, when a timer is active or paused to ensure better accuracy at tracking time. This would be helpful while working through various applications and tabs on a browser to easily see if you missed needing to start/pause/stop the timer. Something simple like a green dot when running, a red dot when paused, and no dot after a timer has been stopped or never used. This suggested change would only be noticed by users of the timer while active or paused. 

Various email and chat applications use a favicon change to provide information to users, such as adding a dot when you get a new email for Outlook or the bubble of WhatsApp changing to a number inside the green bubble when a message is received but unseen.