You might have seen dissimilar types of barcode printed on dissimilar products. That we purchase from market. Barcode are utilized to hide some data. Specific machines are utilized to decode such barcode. But now you can decode such barcodes with assist of your mobile phone.
For this kind of operation compatible devices are S60 3rd Edition, Nokia Nseries, Nokia Eseries.

Here are numerous links of dissimilar Barcode reader applications:

UpCode Reader

Semacode Reader

Nokia Barcode Reader

Kaywa Reader

Glass Reader