With Price Check, you can use your Android phone to check and compare prices instantly on Amazon. And to make in-store price comparison even better, we're introducing a new price sharing feature that helps ensure our prices remain competitive for our customers.

http://www.amazon.com/Amazon-com-Price-Check/dp/B005QTZSRA

The Amazon Mobile App allows Android users to browse and “Shop by Department”, quickly search, compare prices, read reviews, share products with friends, access Gold Box Deals (US only), and make purchases on Amazon.com.

https://play.google.com/store/apps/details?id=com.amazon.mShop.android&hl=en