They tried to do a runaround on the App Store:
"Apple, concerned about the rising competition, decided to sabotage Puffin in order to protect the billions of dollars of search revenue from Google. Puffin releases were rejected citing app review guideline 2.5.6: โApps that browse the web must use the appropriate WebKit framework and WebKit Javascript.โ Our server-side web browser is based on Chromium instead of Appleโs WebKit, therefore, Puffin is rejected."
Not too keen on a dev team that aims at grandstanding when they know the "Webkit or death" policy. Live by the walled garden, die by the walled garden.
Apple doesn't want any browser to gain any perf advantage over Safari so it forces every browser to use Webkit on the backend on iOS. There's no getting around it, and basing your business strategy around getting past gatekeeping policies is incredibly stupid.
@Melezh
According to the news a few months ago
https://hackernoon.com/its-time-to-bringappletojustice-cf12ce860932