Kaspersky QR Scanner: This app is developed by a well-known and trusted security company, making it a reliable choice for scanning QR codes. It can also scan barcodes and has a feature that checks the safety of links contained in QR codes.
Android: Google Play

QR Reader for iPhone: This app is specifically designed for iPhones and has a simple and intuitive interface. It can scan QR codes and barcodes quickly and accurately, and it also includes a feature to create and share your own QR codes.
iPhone: App Store

Native Camera App: Did you know that you can use the camera app on your iPhone or Android device to scan QR codes? Simply open the camera app and hold it up to the QR code to scan it.