Actually, it's not that simple. There are a couple ways to load websites on iOS:

* UIWebView: Old, slow, but dead simple.

* WKWebView: The new "WebKit" drop-in replacement for UIWebView. It uses Safari's Nitro engine, and allows for full customization for the chrome, but does not allow for content blocking. Most new apps use this.

* SFSafariViewController: A "Safari view"; you have no control over the UI chrome (or browsing history, etc.), but it uses Nitro and loads content blockers.

* Safari app: The actual app. Loads content blockers.