You can use Google Slides to create a timer. I created a slide for every second. Click here for the Google Slides file.
Publish to the Web
Use the File menu in Google Slides to choose “Publish to the web.” Publishing allows you to “Start slideshow as soon as the player loads.” Change from the default of every 3 seconds to every second. Copy the “Publish to the web link” and use this to display the timer. The slides will automatically advance each second, showing a timer.
After copying the “Publish to the Web” link to your clipboard, use Control T to make a new tab. Control V to paste the link and press enter.
If a 3 minute timer is something you might use often, Bookmark the “Publish to the Web” link to your Chrome bookmark bar to have fast access to it. Click the star icon in the Google Omnibox address bar to add it to your bookmarks bar.
Customize the Slides
Why Google Slides? Why of course so you can add your Bitmoji to it 🙂 As the timer counts down add an inspirational message that will last for 1 second. Tips or reminders for what they should be doing for this 3 minutes…. If you want the Bitmoji or message to last for more than 1 second, copy and paste it to multiple slides in a row.