Under 'My Assignments' you will find the job to be checked in

To check into an assignment there is a tolerance time that has been entered by your employer.  

The 'Check-In' option is located at the bottom of the assignment details.

Once the option has been selected, the QR code must be read in.

When you leave for breakes or at the end of the working time it is possible to send another Check-In. 

Whether you have to check in and out during the breaks is determined by your employer.