A free app for Android, by DroidLa.
QR Droid allows you to quickly create and share a QR Code, Barcode, and Data Matrix. You can also import, create, use, and share data in a matter of taps. QR Droid is a powerful scanner utility that will allow you to do more than just scan and create codes.
The QR Droid app allows you to use your smartphone as a barcode scanner. This application has been designed with the idea that everyone should be able to use their phone as a scanner, regardless of their technical knowledge.
In addition to scanning and creating QR codes, there are other things you can do with this app, including but not limited to organizing your history to easily access the QR codes that you use the most and automatically syncing data to your Google Drive.