1Blocker is in my opinion the best Adblock currently available in the App Store. I've been using content blockers since iOS 9 started to allow their use. I've tried several free apps, and more than a few paid ones that were touted as being "the best". My most recent disappointment was purchasing Purity. It was a complete failure. It only worked by using a free app along side it, and then was just hit and miss, allowing ads through, and forcing me to whitelist sites that weren't a problem even without an Adblock. In short...it was a complete wast of time and money.
I had tried 1Blocker's free version, and it worked better than any paid content blocker I had tried. Upgrading to the paid version, although high prices as far as apps go, was a wise decision. While I previously was forced to use 2 content blockers,and a separate cookie warning block, I'm now able to use just 1Blocker, and it works perfectly. Every site that had ads slipping through using other content blockers, including Purify, is now ad free. I haven't had to whitelist any web sites, pages load very fast, there's actual support and the app updates automatically.
This is the real deal, and I'd recommend trying the free version as a test. You'll see how well it works, and gladly spent the money to get the extra features of the paid version.