The barcode scan app is a web-based app. To get the most out of the Barcode Scan App, use Google Chrome as your web browser. This browser supports the latest developments.
Open Chrome and navigate to / and log in. After logging in, you will receive a prompt to add the Barcode Scan App to your home screen:
Press add to install the app. The app will then be added to your home screen:

If you do not receive a prompt to add the app to your home screen, select this option from the Google Chrome menu:
Install the app on an iPhone
Installing the Barcode Scan App on an iPhone works slightly differently. Open Safari and navigate to /app/
Press the share icon at the bottom centre of the screen.
Then press Add to Home Screen. An icon will be added to your home screen from which the app can be opened directly.