Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.
QuickMark - QuickMark makes everything possible.
Keepa - Price history charts and the option to be alerted on price drops for all Amazon sites.
QR Code Reader “Q” - Formerly QR Code Reader “Q,” now QRQR, is a smart code reader application.
Fetchee - Fetchee is a free price tracking wish list app that works with all online stores worldwide.
Lynkee Reader - Lynkee Reader is the best QR & Barcode Reader application on the market.