App makers say a growing group of “cloners” are mimicking their products or misappropriating their names and images to ride an original app’s success

Updated March 4, 2013, 8:05 p.m. ET

Clone Wars Roil App World

By AMIR EFRATI

In the fast-paced mobile-apps business, creating a hit app is no guarantee of success: Developers must also fend off the copycats.

App makers say a growing group of “cloners” are mimicking their products or misappropriating their names and images to ride an original app’s success.

The copycats often target top-selling apps and seek to siphon off users and potential revenue. Others carry malicious software. Despite their proliferation, app stores run by GoogleInc. GOOG -0.84% and others have been unable to weed them out.

Consider the experience of WhatsApp Inc., a Mountain View, Calif., company that makes a mobile-messaging app that has been downloaded hundreds of millions of times since its 2009 launch. After WhatsApp reached the top of the app-store rankings, WhatsApp employees noticed that other apps were hijacking its name to ride its coattails.

Today in Google’s app store, alleged WhatsApp clones include “Whatsapp Nearby,” “Whatsapp Friends,” and “Whatsapp Add Me”—none of which were made by WhatsApp but which allow users to contact each other and make new friends. Those three apps, which were made by the same developer, have been downloaded hundreds of thousands of times. The developer denies they are copycats.Clones are “becoming a real problem for us,” said Neeraj Arora, WhatsApp’s business chief. “It does damage to our brand and creates confusion.” It also costs WhatsApp revenue, he said.

WhatsApp costs 99 cents on the Apple Inc. AAPL +0.51% app store, and it is free on Google Android devices for the first year but then costs 99 cents a year after that. Many of the alleged WhatsApp clones are free and generate revenue by showing ads.

Mr. Arora said it is difficult to gauge exact revenue loss but added that he frequently asks WhatsApp’s lawyers to contact app stores to request that offending apps be removed.

There is little data on how many cloners exist and how much money they are reaping, but the practice can take many forms. Some cloners simply copy the images of a well-known app or use the app’s name to cash in on the original app’s popularity.

Others employ special software to copy the app in its entirety and swap out its automated advertising provider with one of their own choosing, allowing them to generate ad revenue that would otherwise flow to the legitimate app maker.

Still other perpetrators copy apps and inject them with malicious software that causes a victim’s phone to automatically send costly text messages.

“With any new technology there are new ways for people to engage in fraud,” said Kevin Mahaffey, co-founder of mobile-security-software maker Lookout Inc. Lookout said it recently found a text-generating strain of malware in a copied version of the “Angry Birds Space” app on Anzhi, an app store in China for Android devices.

“Angry Birds” maker Rovio Entertainment Ltd. didn’t respond to requests for comment. Anzhi didn’t respond to a request for comment. Mr. Mahaffey said Lookout is working with wireless carriers to identify the text-billing fraud caused by clones.

App developers said cloning is typically a bigger problem in alternative Android app stores—stores created where there are no official stores operated by Google—in countries such as China, where the official Google Play app store isn’t available. But developers said cloning is also prevalent in top mobile-app stores run by Apple, Google, Microsoft Corp.MSFT -0.84% and Amazon.com Inc. AMZN -1.63% Those four companies declined to provide data on the cloning issue.

Among those app stores, developers said cloning is most widespread in Google Play. Google Play, unlike the other app stores, doesn’t use humans to vet new apps before they are available for download. A Google spokeswoman declined to comment on how common clones are in Google Play.

Still, spokespeople for Google and Microsoft said victims of cloners can file app-takedown requests and that the companies automatically encrypt many new apps to help prevent some forms of cloning. Amazon declined to comment.

Apple, meanwhile, generally connects the alleged victim of a cloned app—the developer of the original app—with the alleged perpetrator via email and asks them to sort out the dispute, said developers who have gone through the process. If there is no resolution, Apple within weeks will decide whether to pull down the alleged cloned app, developers said.

Some app makers have sued each another for alleged copyright infringement. Game maker Electronic Arts Inc. EA -1.74% last month settled with game-app pioneer Zynga Inc.ZNGA +13.03% following allegations last year in federal court that Zynga’s mobile game “The Ville” effectively copied EA’s game “The Sims.” Zynga denied the allegations.

For developers, a cloned app can take months to remove. David Barnard, a 34-year-old developer from San Marcos, Texas, fended off several alleged copycats in the Apple app store over the past year.

Mr. Barnard’s Launch Center app helps iPhone and iPad users create shortcuts so they can perform popular tasks more quickly. The alleged copycats, called Quick Launch and Voice Launch Pro, surfaced last spring. The first was free but 99 cents for a bonus feature, while the second cost 99 cents to download, the same as Launch Center at the time, said Mr. Barnard, who downloaded both apps.

Mr. Barnard said both were nearly identical to Launch Center except for their color scheme, which substituted red coloring for the black used in Launch Center, and included a voice-related feature.

Last May, Mr. Barnard emailed a complaint to Apple about the apps. Apple encouraged Mr. Barnard to work it out with the apps’ creator, Jiqun Zheng. Apple was copied on the emails between Mr. Barnard and Mr. Zheng, who argued that many apps had “similar features.” The Wall Street Journal reviewed the emails.

By late August, Apple informed the parties that it would remove Mr. Zheng’s two apps from its store, and then followed through with removal. In an email, Mr. Zheng, who separately created a successful app called the Mercury Browser that even Mr. Barnard said he enjoys, said that the now-removed apps were inspired by “some other apps” and had unique features. He said they generated up to $2,000, but that it cost more than that to build them.

As for WhatsApp, it is working to remove alleged cloned apps from the Google Play store and said Google’s policy-enforcement team has been “responsive.”

The developer of three of the alleged WhatsApp clones, which generate revenue with graphical ads, calls himself Freek Martens and said he is from the Netherlands. In an email, he said he makes “just enough” revenue from ads on the app “to cover the expenses and finance new projects,” but he declined to be specific.

The developer, who denied the apps are copycats, acknowledged he didn’t have the right to use WhatsApp’s name and that some people might think his apps were officially associated with the original WhatsApp.

But he argued his apps help WhatsApp because users of his products can make new contacts that then get stored on their phones. If those users later turn on the original WhatsApp app, WhatsApp will be able to scan those users contacts list and allow them to chat with more contacts using WhatsApp, he said.

WhatsApp’s Mr. Arora disagrees. “We don’t want more developers using these tactics,” he said. “It dilutes the experience WhatsApp is looking to provide to its users.”