If this sounds like your week
If the timer is private, the collaboration is off.
If you are evaluating “TimeFence vs tray based timers,” you are probably optimizing for a real work session: a pairing call, a recording session, a long writing block, or a long analysis block. A tray icon does not help clients or teammates, and a browser tab is one Alt-Tab away from disappearing. A HUD is the straightforward answer: a clock that is visible in the work plane, without turning “focus time” into a maze of sign-ins and dashboards.
Where tooling usually breaks
A hidden timer is a private clock. Private clocks cause drift.
If you are comparing options for “TimeFence vs tray based timers,” count what happens when the screen is shared, when a clip is rendering, or when you are deep in a pair session. A HUD is legible in the same place as the work, which is the difference between time-boxing and time-guessing.