If your employees cannot see the Time clock in their mobiles apps, please check the following:
That your Time clock has been activated. Click the Time Clock on your side bar>more>activate
Once the Time Clock has been activated, make sure it is assigned. For that, click more>edit assignment. Assign the Time Clock to the group all users if you want all your existent and future employees to be able to see the Time Clock.
By default, every new employee that you add will belong to the smart group all users.
Done! Ask your employee to close the app and open it again to start clocking in and out.