If you are using PigVision Mobile Sows to register in the stable, you can add a QR-code to the printed sow card and use your phone or tablet to scan the QR-code to find the sow. See how to add the QR-code to the printed sow card on this link: https://help.pigvision.com/en/support/solutions/articles/60000708531-add-qr-code-to-sow-card
To be able to scan the QR-code on the sow card with the app you tap on the symbol next to the search field or the heading text. This symbol is marked with a green circle in the picture below:
Then the camera will be turned on and you can scan the QR-code on the sow card.