Do all browsers on iOS use WKWebview or UIWebVIew?

问题:

I am curious about third part browser on iOS（Chrome or FireFox）

Does all of them use the WkWebview or UIWebVIew to show then web page, but do many extra work like cache etc?

So, if I want to write a browser on iOS, I must use WkWebview to show the web page and wrapping it to do more stuff？

回答1:

Yes, Apple forbids other web engines explicitly (or only allows the WebKit respectively) in § 2.5.6 of App Store Review Guidelines:

2.5.6 Apps that browse the web must use the appropriate WebKit framework and WebKit Javascript.