ZXing - Barcode Scanner for Android
Barcode & QR Code Scanner - A free app which allow to read and generate barcodes for Android.
QuickMark - QuickMark makes everything possible.
QR Droid - QR Droid Zapper
NeoReader - The NeoReader is a universal barcode scanning app that transforms your mobile phone into a barcode scanner, allowing access to mobile web content by scanning codes from virtually any medium
Kinoni Barcode Reader - Use your iPhone as a professional barcode scanner for your PC or Mac.