The state of California, the Federal Trade Commission and the U.S. Senate are all breathing down the ad industry's neck about mobile data privacy. Today, its biggest privacy self-regulatory group is responding. The Digital Advertising Alliance will unveil its mobile ad privacy app today at its annual summit in San Francisco, opening it up to evaluation by its ad-network, agency and brand participants.

Put simply, the app will let people opt-out from receiving mobile ads targeted based on the apps they interact with.

When available for free download by consumers later this year, the DAA AppChoices app will act similarly to the organization's current privacy program, which allows people to opt-out from online behavioral ad targeting, signaled by a tiny triangular blue icon in the corner of digital ads.

"It's about getting this in front of the DAA participants and showing them what it looks like," said DAA Managing Director Lou Mastria.

The app should be available to consumers in the fall. It will give people the choice of opting out from ads served by select mobile ad providers, or from all companies involved in one fell swoop. The number of consumer-facing privacy technologies is growing; it is unclear whether the addition of another self-regulatory tool offering a surfeit of options to everyday mobile phone users will make much impact on the amount of data flowing through the mobile ad ecosystem.

Mr. Mastria said the DAA will "be doing a bigger push" to market the app to people when closer to launch.

A key difference between the mobile program and its web-ad counterpart is the fact that cookies essentially do not function in the mobile environment. So, rather than build a system that uses cookies to notify ad servers when someone has opted-out from behavioral ads, the app's designers had to take a more complicated route.

The app is operated on the back end by Ghostery, which has its own similar app for mobile ad privacy. The company has mapped the array of signals mobile ad firms use to track and target mobile users, and employs that information to notify those systems when someone has opted-out from receiving behavioral ads.

The app will prevent people from seeing ads that are targeted based on the apps they use, the mobile equivalent of online behavioral targeting (which segments audiences based on the types of web content they view). However, it won't prevent mobile location-data collection, use or ad targeting based on location data. According to Mr. Mastria, the DAA does require that group participants obtain consumer consent for collection or use of precise location information. In other words, when people download apps that ask to use location data, their location information still could be gathered, shared or used, even if they opt-out of ad targeting through the DAA app.

Phillip Zakas, co-founder of mobile location-data firm Gridskippr, said the concept of a mobile app for cross-app data privacy has merit; however, he argued that most consumers are not aware that mobile location data can be fed back to ad networks by apps when the apps collect it for ad targeting. "The industry has to be more explicit about how location data is being used, how it's being collected and how it's shared," he suggested.

Mobile location data and related privacy and security issues have been on government radar recently. The Senate Judiciary Subcommittee on Privacy held a hearing in early June to discuss the Location Privacy Protection Act, which primarily aims to make it harder for stalkers to use mobile tracking technology to find their targets. The proposed law could also curb some emerging mobile location tracking technologies that straddle the line between consumer conveniences and consumer privacy infringement.

Meanwhile, the FTC has scrutinized mobile data collection. In addition to inspecting how mobile apps gather data about kids, the agency's Mobile Technology Unit in May revealed research showing how health and fitness apps often disseminate data to third parties including ad firms, unbeknownst to users.

Jessica Rich, director of the FTC's Bureau of Consumer Protection is set to deliver a luncheon keynote at the DAA's summit.