When it comes to U.S. Android mobile shopping app downloads, Amazon is king of the forest and eBay still gets a winning bid with many consumers. However there are some notable differences in Android shopping app use since January, the last time digital analytics firm SimilarWeb provided exclusive analysis on shopping apps to Mobile Strategies 360. Perhaps most notably, in April consumers used the big players’ shopping apps less frequently than they did three months prior.

SimilarWeb provides to Mobile Strategies 360 the top 10 apps each month in a range of verticals based on U.S. Android (tablet and smartphone) installs and daily active users. In addition to ranking the Top 10 apps, the index also looks at two other telling metrics within each of the Top 10 apps: app retention or, the percentage of users with an app who open it at least once within 30 days after installing it; and the percentage of each brand’s total web traffic that goes to its mobile site.

30-day retention rates decreased dramatically in April from January for the shopping apps of the biggest conventional players (eBay, Walmart Stores Inc. and Amazon) on the list, says Pavel Tuchinsky, digital insights manager for SimilarWeb. By comparison, newer garage-sale-style shopping apps, such as OfferUp and 5miles improved their 30-day retention rates in April. Both of those apps also allow consumers to buy and sell products locally.

For April, Amazon.com Inc. holds the title of the most installed shopping app—installed on 36.15% of all Android devices. The old version of the online giant’s app has a 5.40% 30-day retention rate. This is down from the 10.00% retention rate in January, Tuchinsky says. In addition, Amazon’s new default app, Amazon Shopping, ranks No. 3 in installs, holding a spot on 12.56% of all Android devices in the U.S. Its retention rate in April is 5.19% compared to 7.99% in January.

EBay Inc. ranks second for installs in April, with 17.52% of all Android devices in the U.S. Its retention rate is 5.17% compared with 8.05% in January.

Walmart’s app ranks No. 7 in installs with 8.20% and its retention rate fell to 3.89% from 6.45% in January.

Meanwhile, the OfferUp app improved retention to 7.19% in April from 7.08% while 5miles improved retention to 5.21% from 3.92%.

A new entrant to the top 10 list since January, letgo: Buy & Sell Used Stuff, enables consumers to users buy and sell personal items locally. “Its popularity underlies the fact that local discovery and the ability to sell off things you are not using anymore is in high demand,” Tuchinsky says.

AliExpress is another newcomer to the list in April. AliExpress.com, part of China’s massive online company, Alibaba Group Holding Ltd.’s is a global marketplace with more than 200,000 mostly Chinese sellers and 100 million products in 40 categories, including health and beauty, apparel and accessories, consumer electronics and furniture. “It managed to break through into the most used shopping apps in U.S. after massive advertising and aggressive user acquisition,” Tuchinsky says. AliExpress employs a number of successful strategies to maximize app installs and use, including offering discounts to customers for app-based purchases, he says.

When it comes mobile’s share of web traffic compared to desktop, nine out of 10 of the companies on this list get more than half their site traffic from mobile devices, SimilarWeb says. And, for three players on the list, more than 70% of traffic stems from mobile devices.