Features to help shoppers in store, such as product scanning, are among the most popular mobile app features for Fortune 500 retailers with apps, according to a new study from retail app platform Branding Brand Inc.

Branding Brand analyzed 25 iPhone retail apps and their features in light of Apple Inc.’s 10-year app store anniversary this July.

Some basic features, such as infinite scrolling on a page dedicated to a  category of products (88% of retailers offered this), geolocation (88%), product reviews (80%) and order tracking (76%) were among the most popular features retailers offered.

Several retailers offered in-app capabilities to help shoppers in store. For example, 72% of retailers’ apps allowed shoppers to scan products, and nearly a quarter of apps, 24%, had an in-store mode for shoppers. At a simple level, 80% of apps allowed shoppers to look up store locations.

Only 20% of the apps offered the option to reorder a product. For example, in Amazon’s app, shoppers can easily pull up the products they’ve ordered before and hit order again.

Branding Brand also found:

• 76% of retailers offered the ability for shoppers to mark favorites, registry or wish list items.
• 16% of apps had Apple Pay.
• 24% of retailers had app-exclusive deals. For example, Macy’s offers 25% off first app orders.
• 12% of retailers offered some form of augmented reality.
• None of the apps incorporated virtual reality.

Apps can be an essential part of a retailer’s mobile strategy. Of the 1,000 retailers in Internet Retailer 2018 Top 1000, 254 retailers had an app in 2017. Even though a small percentage of a retailer’s customers will use its app, those users are often the most loyal shoppers, and the app has a much higher conversion rate than its website.

In fact, the average conversion rate in apps is between 14.9% and 20.4%, mobile app marketing firm Liftoff said in its recently released report, “Mobile Shopping App Report.” The report is based off of its retail client data from 45 retailers, based on 10.2 million app installs and 1.8 million first-time purchases between April 2017 and April 2018. Plus, of the 254 retailers Internet Retailer tracks with mobile apps, those retailers have a repeat customer rate of 44.8%, according to Top500Guide.com.

In contrast, Internet Retailer estimates that the average conversion rate for the Top 1000 online retailers is at 3.02%, which is an average of desktop, mobile and app conversion, and those retailers’ return shopper rate is 38.4%.

But, getting these high-converting shoppers isn’t cheap. The cost for a retailer to get a consumer to install the app is $4.11, and the cost to get that consumer to purchase in app is $58.35, according to Liftoff data.

What’s more, only 7% of consumers who install a shopping app go on to make a purchase, according to Liftoff data. On average, it takes 8.5 days for a consumer to make a purchase from the time she downloads the app for marketplace apps, compared with 12 days for a branded retailer app.