By default, the "Track Time/Check-In" button is enabled only for the Mobile Time Tracker app. Track Time/Check-In button can be enabled for other apps in salesforce lightning mode.
More details below to enable the Track Time/Check-In button for other applications
- Log in to Salesforce as Administrator
- Click the Gear (Settings) icon and go to Setup
- From Quick find box, search for App Manager and click it
- Search for the App Name you would like to enable the "Track Time" button and click edit (for Lighting App type)
- Click the "Utility Items" from the App settings list
- Click on Add Utility Item button
- Search for "Checkin_Checkout_action" and click it
- Then rename the Label as per the org requirement
- Choose Icon from the list
- Set the Panel Width and Panel Length
- Click the Save button.
Now the "Track Time" button is enabled for Check-In and Check-out for the selected App Name from the App Manager list.