A retired phone still has so many uses.
Turn an old smartphone's camera into a QR/barcode scanner. Just install an app and start using it right away.
See How to UseMount an old phone at the front desk as a dedicated clock-in terminal. Keep an attendance app or a simple punch-in page open on it.
See How to UseInstall a remote-camera app and set the phone in place to turn it into a network camera you can view live from anywhere.
See How to UseCombine it with a QR payment app or a card reader to use it as a point-of-sale terminal.
See How to UseInstall a home-security app and mount the phone in place to get a surveillance camera with motion detection.
See How to UseDedicate it to product photography and send the photos straight to the cloud or the website.
See How to Use