Called Focus by Firefox, the app released Tuesday works a lot like other blockers for Apple’s mobile platform: users download the app from the App Store, and open it to select the sort of content they want to block. After that, they just enable it as a content blocker in their phone or tablet's settings.
Focus allows users to block several different types of code that track their behavior across websites, including ad trackers, analytics trackers and social trackers. The app will block the same content as Firefox's Private Browsing with Tracking Protection feature on Windows, Mac, Linux and Android.
That means ads that don't track users will be allowed through Focus, giving advertisers and publishers a way to make money off those people who have the app enabled. The list of blocked ads is primarily provided by Disconnect, a company that makes a browser extension focused on blocking trackers. It is open source, publicly viewable and doesn't allow or require companies to pay in order to get their ads unblocked.
"We made Focus by Firefox because we believe content blockers need to be transparent with publishers and other content providers about how lists are created and maintained, rather than placing certain content in a permanent penalty box," Mozilla Chief Legal and Business Officer Denelle Dixon-Thayer wrote in a blog post. "We want this product to encourage a discussion about users and content providers, instead of monetizing users’ mistrust and pulling value out of the Web ecosystem."
Another interesting component of the Focus announcement is that Mozilla is providing the app free of charge, and says that it doesn't monetize the blocker through other means. It's another sign of one of the interesting things about Mozilla as a browser-maker: the organization doesn’t operate an advertising network like its largest competitors, and so it can afford to make a stand about tracking users.
Interestingly, Focus works in Safari on iOS but not Firefox, since Apple doesn’t allow third-party browsers to use the Content Blocker functionality. Firefox's Vice President of Product Nick Nguyen wrote in a blog post that Mozilla is looking into how it can bring similar functionality to its browser on Apple’s mobile platform.
Mozilla has gone from avoiding Apple’s mobile platform to supporting it wholeheartedly. The organization previously refused to offer Firefox for iOS because Apple doesn't allow third-party browsers to use their own rendering engines. That policy stance changed this year when the company launched its browser for Apple's platform, and carries on with this announcement Tuesday.
These moves may be driven in part by Firefox’s dwindling market share. By providing users more control over how their data is shared with advertisers, Mozilla may attract people who want to take a principled stand with their browsing to its applications.