Open AdBlock is a free and open source content blocker for iOS that has been written from the ground up to support both 32- and 64-bit devices. As you may be aware, Apple blocked the ability to load content blockers for 32-bit devices (those with a A6 chip or older) in a late developer beta of iOS 9. Open AdBlock circumvents this restriction by redirecting Apple's loading checks and making them succeed, using Facebook's excellent fishhook library. Once the verification is bypassed, Open AdBlock simply uses private SafariServices APIs to load and enable the extension. Unfortunately, this makes it impossible for Open AdBlock to be available on the App Store–if you'd like to try it out, you'll have to build it youself.