With apps becoming more popular as a way to shop, it is up to brands and developers themselves to watch for fakes and report them, much as they scan for fake websites, said Ben Reubenstein, chief executive of Possible Mobile, a Denver company that makes apps for JetBlue Airways, the PGA Tour and the Pokémon Company, among others.

“It’s important that brands monitor how their name is being used,” he said.

Apple removed hundreds of fake apps on Thursday night after The New York Times inquired about the specific app vendors that created many of them. Other apps were removed after a New York Post article last week drew attention to some of the counterfeits.

“We strive to offer customers the best experience possible, and we take their security very seriously,” said an Apple spokesman, Tom Neumayr. “We’ve set up ways for customers and developers to flag fraudulent or suspicious apps, which we promptly investigate to ensure the App Store is safe and secure. We’ve removed these offending apps and will continue to be vigilant about looking for apps that might put our users at risk.”

In September, Apple also embarked on a campaign to review all two million apps in the App Store and remove “apps that no longer function as intended, don’t follow current review guidelines or are outdated.” The company says that a significant number of apps have been removed and that the review is continuing.

Despite Apple’s efforts, new fake apps appear every day. In some cases, developers change the content of an app after it has been approved by Apple’s monitors. In other instances, the counterfeiters change their names and credentials, and resubmit similar apps after one round of fakes is discovered.

“It’s a game of Whac-a-Mole,” Mr. Mason of Branding Brand said.

On Friday, for example, an entity calling itself Overstock Inc. — an apparent attempt to confuse shoppers looking for the online retailer Overstock.com — was peddling Ugg boots and apparel through a fake app that was nearly identical to one banished by Apple on Thursday.

Image A fake Michael Kors app, claiming to be connected to Nordstrom. Some counterfeits are more convincing than others.

The same Chinese app developer, Cloaker Apps, created both fake Ugg apps on behalf of Chinese clients.