Emerging Smart phones are poised to give a whole new dimension to the way we shop, bank, and go about many of our everyday activities. iGrocer is a smart grocery shopping assistant, that re-defines grocery shopping. It is capable of maintaining nutrition profiles of its users. Particularly useful for elders and disabled shoppers, iGrocer can aid and advice users on what products to buy and what to avoid based on nutrition criteria and price constraints. Implemented on a smart phone with a barcode scanner accessory, iGrocer has a number of killer features that include: (1) ubiquitous shopping list: adding items to the shopping list by different means (e.g. simply scanning them when near empty, scanning and storing manufacturer coupons, planning the weekly menu right on the phone or through the web, and shopping for the necessary ingredient of a particular recipe, (2) quick and assisted in-store shopping: while shopping in the grocery store, iGrocer maps out the shortest shopping path with a map indicating the location of the next item on the list, and (3)automated check-out: iGrocer is capable of acting on behalf of the store and the customer to perform a trusted queue-less checkout. In this "application-oriented" paper, we present the iGrocer concept and give details of its architecture and implementation. We also summarize the lessons learnt throughout its development and testing phases.