Yes, the location can be tracked for Clock-In/Out and for Check-In/Out using the PK4 TimeTracker application.

There is an alert message on the device when you log in to the PK4 TimeTracker application: "Allow Time Tracker app to track your Location", with options like "Deny, and Allow". Click the Allow button and the PK4 TimeTracker application starts tracking the location for Clock-In/Out and Check-In/Out.

The location details are saved and shown in Salesforce in the TT Details tab as in the screenshot below.

Note: The location tracking should be enabled in the PK4 TimeTracker configuration screen in Salesforce, by following the instructions here. Only then do the users see the message as 

"Allow Time Tracker app to track your Location" when they log into the PK4 TimeTracker application on the device.

Also, enabling the location tracking the app takes 1 to 1.5 seconds extra for Clock-In/Out and Check-In/Out screens. This is because the location is tracked and saved in Salesforce.