Mozilla today launched Focus by Firefox, a free content blocker for iOS. It isn't the first content blocker to hit the market for Apple's mobile platform, but it is the first to bring Firefox's specific brand of Private Browsing with Tracking Protection to Apple's smartphones.
Focus by Firefox works by letting folks blocks specific kinds of trackers for things like ads, social media and more. The idea here is that blocking these items can improve performance and prolong battery life for those folks browsing the Web for any amount of time on their phone. In practice, people generally seem to just want control over every aspect of what they're presented with on the screen — which is more than fair. It's their phone, after all.
Mozilla's also made a whole separate post about why it made Focus in the first place, and it's an interesting read. However, the gist is summed up the post's third paragraph:
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. 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. Focus by Firefox is free to users and we don't monetize it in other ways.
Essentially, the argument it makes is that how and where content is monetized on Web browsers isn't clear. Focus by Firefox takes the high ground with a commitment to transparency. It has even based at least some of its content blocking on a publicly-available list provided by Disconnect.
Focus by Firefox is currently available in the App Store, but with an interesting twist: it only functions with Safari on iOS — as in, the iOS content blocker by the folks behind the Firefox Web browser doesn't work on the iOS version of Firefox. According to Mozilla's release announcement, this isn't by choice as Apple specifically prevents content blockers from working on third-party browsers.