From the Barcode to the Back Pocket: How Mobile Rewired Grocery Retail

The barcode scanner has been in grocery checkouts for decades. For decades, the checkout was the primary digital touchpoint between shoppers and grocery retailers.

Then the smartphone moved that relationship into the shopper’s pocket. What followed wasn’t a clean, orderly evolution. It was a series of bets, some that paid off, some that blew up publicly, and a full rethinking of what it means to buy groceries in 2025.

How did grocery apps start?

The first wave of grocery apps wasn’t about checkout or delivery. It was about the shopping list.

Starting in the early 2010s, major retailers built apps that digitized what shoppers already did on paper: writing down what they needed, clipping coupons, checking prices. Not glamorous. But it trained consumers to open the retailer’s app before leaving the house.

Loyalty programs followed. The plastic card at the register migrated to the smartphone. Suddenly, retailers had a direct channel to the shopper: push notifications, personalized offers, purchase history. Kroger launched Kroger Pay, combining payment, loyalty, and digital coupons into one experience on the phone. It was one of the first clear signals that the app wasn’t just a convenience feature. It was becoming the backbone of the customer relationship.

What is Scan & Go, and why did it take off?

The idea was straightforward but required changing decades of behavior: shoppers scan items as they shop, pay from their phone before leaving, and never touch a register.

Sam’s Club had it running before anyone paid attention. When the pandemic hit, Sam’s Club said member adoption of Scan & Go had doubled from the year before. The technology hadn’t changed. Consumer behavior did, and the tech was already there.

Sam’s Club read that signal clearly. In 2025, it announced plans to remove traditional and self-checkout lanes across its nearly 600 clubs, making Scan & Go the centerpiece of its checkout strategy. Grocery Doppio reports that the new AI exit arches cut average exit time by 23% compared with manual receipt checks. It also cites an Incisiv study in which 79% of retailers said the technology lifted customer experience and 58% reported lower front-end labor costs.

The model works because every visit becomes a logged event. Every scanned item is a data point. Every completed purchase is a behavioral signal the retailer can use to personalize the next visit.

Who are the omnichannel shoppers worth building for?

In Grocery Doppio’s Digital Grocery: Year in Review, omnichannel shoppers made up 19% of the customer base. They spent an average of $1,043 a month and showed a 25.6% margin.

That small group is a powerful signal of where digital investment can create value.

The wider market is moving the same way:

• Online grocery is growing fast. One forecast, from Market Data Forecast, puts U.S. online grocery at $217 billion in 2025 and $893 billion by 2034, about 17% a year. Other analysts forecast lower totals, such as IMARC’s $203 billion in 2025 and $712 billion by 2034, but all point up.
• Pickup and delivery are close. FMI and NielsenIQ’s 2025 report found 31% of shoppers using curbside pickup and 29% using same-day delivery. By April 2026, FMI said delivery and shipping were growing faster than pickup.
• Gen Z is already online. FMI reports that 84% of Gen Z shoppers buy groceries online at least occasionally, compared with 67% of shoppers overall.

For a generation that has grown up with digital shopping as a normal part of everyday life, mobile isn’t a new channel. It’s part of the expected experience. What they expect today becomes the standard tomorrow. Every week a retailer operates without that digital layer is a week a competitor spends building data, loyalty, and a gap that gets harder to close.

What does it take to build a grocery app that works?

The hardest part of building a grocery retail app isn’t the app. It’s everything behind it.

Most retailers already have a POS, inventory, loyalty, and commerce infrastructure in place. The challenge is making those systems work together in a way the shopper never has to think about. When you build a mobile experience on top of disconnected systems, the shopper feels every gap: an item that’s in stock on the app but not on the shelf, a loyalty discount that doesn’t apply at checkout, a Scan & Go flow that breaks under load.

We start with what you already have. Our job is to connect your existing POS, inventory, and loyalty systems into a single mobile layer that works as one, without forcing a wholesale replacement of your infrastructure.

In practice, that means:

• Integrating your backend systems into one app that handles loyalty, payments, and Scan & Go.
• Surfacing inventory data from your existing systems so shoppers can see availability when and where it matters.
• Giving your team a clear picture of shopper behavior (what they buy, when, and how often) that you can act on.

The shoppers who spend the most are not waiting. Neither should you.

Shockoe designs and builds mobile apps for retailers who want to turn digital experience into a real competitive advantage. Contact us.