In the Estimates screen, you will be able to see a bubble notification if there are any other users working on that particular Estimate at the same time. The bubble displays the initials of the user who is working on the same estimate. You will be able to see the bubble notification even if you navigate to any page within an Estimate.
You will be able to see more information on the other user, action they are performing and the time duration of their presence on that estimate by moving your mouse on the bubble notification.
This bubble will appear when other users from your account (or tenant) are performing any of the below actions on an Estimate at the same time,
1. viewing the Estimate
2. editing the same Estimate
3. saved any changes over your changes
The bubble will disappear when the other user leaves the estimate either by navigation or closes the browser/tab.