LogQuillTimer
Time your work as you do it, then log it in one click.
Who: everyone whose role tracks time.
The timer sits at the top of the Time Tracking page, and can also be added to your dashboard. It is also in the LogQuill worklogs panel on Jira issues, where it starts on that issue: it is the same timer everywhere.
Choose an issue: search for one, or pick from Recently viewed in Jira. You can also start first and choose the issue later.
Start. Pause and Resume as you need.
Stop & log opens Log time with the issue and the time filled in. Check it, then log it. To throw the timer away without logging anything, use the reset button (the round arrow), then Discard; Keep tracking lets it run on.
The timer keeps running if you leave the page or close Jira, and picks up where it was when you come back in the same browser. It is kept in that browser only: it doesn't follow you to another computer. The time is logged on the day you started it, even if you stop it after midnight.