Before you use the LanguageScreen app we recommend you download and read the user guide. The User Guide is also accessible from the LanguageScreen app via the "?" icon (question mark) in the header. Each list of QR codes you generate comes with a Practice QR code. You can use this Practice Session QR code as many times as you need to run through the assessment and practice before assessing any children. Please note that data from a Practice Session is not saved and therefore you should never use the Practice Session QR code when assessing children.