Walmart is launching new or revamped iPhone and iPad apps aimed at linking online and in-store shopping like never before, while creating a platform for the relationship-marketing program the giant retailer has long lacked.

Both the iPhone and iPad apps have been designed by the Mountain View, Calif.-based @Walmartlabs unit for use both in the retailer's 3,800 stores in addition to e-commerce. The iPad app appeared in the Apple App Store last week, while the revamped iPhone app is awaiting Apple certification, which Walmart hopes will be coming soon. Walmart released an updated version of its Android app last week as well, but without many of the bells and whistles offered by the forthcoming iPhone app.

The updated iPhone app adds a wide range of tools aimed at shopping in stores, including the option of using home bar-code scanning or Apple's Siri voice command system to create lists. It will integrate those lists with coupons served by Coupons.com and Walmart's inventory systems to show whether desired items are available in individual stores. And starting with a beta test at a select group of stores nationwide, the iPhone app will also help shoppers find individual items in stores.

"Instead of going through your Sunday newspaper to clip coupons, we bring the coupons to you and match them for you, and you can bring them into the store and get a discount," said Gibu Thomas, Walmart's senior VP-mobile and digital, which he hopes will increase coupon redemption.

"We want to make it as easy as possible for our customers to have additional opportunities to save without them having to do the work," he said.

The updated iPhone app also includes a budgeting tool that keeps a running tally of items added to the shopping list, product information that includes reviews, and ability to share lists with family or friends. It will also keep tabs of users' favorite items, which can be used to create future shoping lists, Mr. Thomas said.

Customers who key in a generic item for their lists, he said, will also be able to see a screen showing specific SKUs from their designated local Walmart to select and be in some cases shown promotional offers for the category, Mr. Thomas said.

"Lots of people have tried to create shopping-list capabilities in the past," he said, but Walmart has aimed to surpass them through greater ease of input, such as capitalizing on voice commands and bar-code scanning.

"The real power comes from marrying our store systems with the list you're creating," he said. "We think this will redefine how customers use shopping lists on smartphones."

Walmart customers are adopting smart phones at about the pace of the general U.S. population, Mr. Thomas said, with about a third of them owning them a year ago and about half expected to own them by early next year. Of Walmart customers who have both iPads and PCs, more than half prefer to shop online using their tablets, he said.

A key part of Walmart's mobile strategy is to focus on using the technology to create self-service tools for its 140 million weekly customers.

"In all of our stores, we have access to these world-class supply chain systems and inventory systems that have a lot of information that was only available to the store managers or store associates previously," Mr. Thomas said. "What we're doing now with our mobile applications is surfacing that information and providing it to customers at their fingertips."

The second key is to "use mobile to create a personal relationship with that customer," he said. "The mobile device is the most personal item a person carries, and they carry it with them wherever they go. Using that device we can understand how they shop with us both online and in the store. We can provide relevant recommendations that will help drive our top line and create better conversion, basket size and so on."

Walmart won't immediately flow point-of -sale information from the stores to mobile devices or individual accounts via the iPhone or iPad, but Mr. Thomas said the list-generation capability will give it access to something many shopper-card programs don't have -- data on what shoppers are considering and the ability to make recommendations based on what's already on the shopping list. The mobile apps also will allow for the creation of "favorites" lists based either on past online purchases or prior lists.

The third pillar of Walmart's mobile strategy is to bridge the gap between online and offline shopping.

The iPad app, a more "touch optimized" version of Walmart.com, includes a "Browse My Store" feature for checking product availability and detailed information on specific stores. It's also designed so shoppers can easily find sizes or varieties not carried in their store either while shopping at home or in the store, and order them online, said Mr. Thomas.