Ext Ops Panel
Open dashboard

Classroom Timer

Chrome extension by Teacher-Tool-Box · Productivity · Education

  • Established publisher

A Chrome extension in Productivity · Education with 430 users, barely installed. Audience over the last 30 days: +77.

No site access is declared in the manifest, so it cannot read the pages you open on its own.

What the developer says, and 3 screenshots

Loading from the Chrome Web Store. Open the listing if it does not appear.

Users
430
Rating
5.0 (2 ratings)
Users, last 30 days
+77
Rating, last 30 days
Steady over 30 days
Version
2.0
Updated in the store
2026-10-09
Published
2025-05-28
Manifest
V3
Browser access
5 permissions

How it has moved

Users
+77 since 01.10
353-430 · 18 readings
2026-10-09: gained the good publisher record badge
  1. 2026-10-04355
  2. 2026-10-08366
  3. 2026-10-10375
  4. 2026-10-11370
  5. 2026-10-13367
  6. 2026-10-16387
  7. 2026-10-17386
  8. 2026-10-18384
  9. 2026-10-19388
  10. 2026-10-20393
  11. 2026-10-21402
  12. 2026-10-22407
  13. 2026-10-23414
  14. 2026-10-24417
  15. 2026-10-25419
  16. 2026-10-28423
  17. 2026-10-29430
  18. 2026-10-31430
Rating
unchanged since 01.10
reviewsrating 5.00 · 18 readings
2026-10-09: gained the good publisher record badge
  1. 2026-10-04reviews2rating5.00
  2. 2026-10-08reviews2rating5.00
  3. 2026-10-10reviews2rating5.00
  4. 2026-10-11reviews2rating5.00
  5. 2026-10-13reviews2rating5.00
  6. 2026-10-16reviews2rating5.00
  7. 2026-10-17reviews2rating5.00
  8. 2026-10-18reviews2rating5.00
  9. 2026-10-19reviews2rating5.00
  10. 2026-10-20reviews2rating5.00
  11. 2026-10-21reviews2rating5.00
  12. 2026-10-22reviews2rating5.00
  13. 2026-10-23reviews2rating5.00
  14. 2026-10-24reviews2rating5.00
  15. 2026-10-25reviews2rating5.00
  16. 2026-10-28reviews2rating5.00
  17. 2026-10-29reviews2rating5.00
  18. 2026-10-31reviews2rating5.00
Users
+163 since 01.09
267-430 · 31 readings
2026-10-09: gained the good publisher record badge
  1. 2026-09-01267
  2. 2026-09-02298
  3. 2026-09-04308
  4. 2026-09-06306
  5. 2026-09-07309
  6. 2026-09-08302
  7. 2026-09-09310
  8. 2026-09-13327
  9. 2026-09-16333
  10. 2026-09-21340
  11. 2026-09-25344
  12. 2026-09-27350
  13. 2026-09-28353
  14. 2026-10-04355
  15. 2026-10-08366
  16. 2026-10-10375
  17. 2026-10-11370
  18. 2026-10-13367
  19. 2026-10-16387
  20. 2026-10-17386
  21. 2026-10-18384
  22. 2026-10-19388
  23. 2026-10-20393
  24. 2026-10-21402
  25. 2026-10-22407
  26. 2026-10-23414
  27. 2026-10-24417
  28. 2026-10-25419
  29. 2026-10-28423
  30. 2026-10-29430
  31. 2026-10-31430
Rating
unchanged since 01.09
reviewsrating 5.00 · 31 readings
2026-10-09: gained the good publisher record badge
  1. 2026-09-01reviews2rating5.00
  2. 2026-09-02reviews2rating5.00
  3. 2026-09-04reviews2rating5.00
  4. 2026-09-06reviews2rating5.00
  5. 2026-09-07reviews2rating5.00
  6. 2026-09-08reviews2rating5.00
  7. 2026-09-09reviews2rating5.00
  8. 2026-09-13reviews2rating5.00
  9. 2026-09-16reviews2rating5.00
  10. 2026-09-21reviews2rating5.00
  11. 2026-09-25reviews2rating5.00
  12. 2026-09-27reviews2rating5.00
  13. 2026-09-28reviews2rating5.00
  14. 2026-10-04reviews2rating5.00
  15. 2026-10-08reviews2rating5.00
  16. 2026-10-10reviews2rating5.00
  17. 2026-10-11reviews2rating5.00
  18. 2026-10-13reviews2rating5.00
  19. 2026-10-16reviews2rating5.00
  20. 2026-10-17reviews2rating5.00
  21. 2026-10-18reviews2rating5.00
  22. 2026-10-19reviews2rating5.00
  23. 2026-10-20reviews2rating5.00
  24. 2026-10-21reviews2rating5.00
  25. 2026-10-22reviews2rating5.00
  26. 2026-10-23reviews2rating5.00
  27. 2026-10-24reviews2rating5.00
  28. 2026-10-25reviews2rating5.00
  29. 2026-10-28reviews2rating5.00
  30. 2026-10-29reviews2rating5.00
  31. 2026-10-31reviews2rating5.00

A dot marks a day the store showed a different number. Between them the line carries the last one forward: we read every listing up to 2 times a day and record a point only when something moves. History beyond ninety days is in the app.

What it can reach

No site access is declared in the manifest, so it cannot read the pages you open on its own.

  • Run its own code on the pages it can access scripting
  • Act on the current tab, but only after you click it activeTab
  • Schedule work to run later alarms
Show the remaining 2

The full permission history for this extension

What changed recently

  1. Gained the Established publisher badge
  2. Store badges changed

The publisher

Teacher-Tool-Box publishes 2 listings we track, 493 users between them. Listed website: gradebridge.support.

  1. GradeBridge Teacher-Tool-Box · Productivity · Education · published 2025-11-20 63 users ★ 5.0

Like this one

Listings the catalog judges closest in what they say they do.

  1. Classroom Timer Describes nearly the same job, smaller audience 292 users ★ 5.0
  2. Class Timer Describes nearly the same job, smaller audience 29 users
  3. Timer for Google Slides Describes nearly the same job, smaller audience 5k users ★ 4.5
  4. Visual Timer for Google Slides Describes nearly the same job, smaller audience 141 users ★ 5.0
  5. Countdown Timer for Class Describes nearly the same job, smaller audience 172 users ★ 4.0

The top 5 only. The full comparison, with why each one is close, is on the alternatives page; ranking a whole neighbourhood by your own criteria is in the app.

Want this mark on your extension in our catalog?

Verify that you are its author and you can show this mark on the card, with live banners for your site and README. How verification works

Connect it to Ext Ops Panel and see installs, uninstalls and uninstall reasons as events arrive, not as a weekly summary.

Connect it in a minute See what the panel does
Add a badge to your README or site

The badge shows the audience and rating from our last pass over the store and links back to this page.

Users and rating on Ext Ops Panel

Markdown

[![Users and rating on Ext Ops Panel](https://extops.dev/extensions/inmcnioaifbfnigippdddbgfoofefnnb/badge.svg)](https://extops.dev/extensions/inmcnioaifbfnigippdddbgfoofefnnb)

HTML

<a href="https://extops.dev/extensions/inmcnioaifbfnigippdddbgfoofefnnb"><img src="https://extops.dev/extensions/inmcnioaifbfnigippdddbgfoofefnnb/badge.svg" alt="Users and rating on Ext Ops Panel" height="20"></a>

Figures come from our own regular passes over the public Chrome Web Store listing, last read on . The store last changed these figures on 2026-10-29. We publish no contact details for extension developers.

Where the data comes from: how the catalog is built