Apple’s App Store policy explicitly calls for its Webkit as the browser’s rendering engine, but that hasn’t stopped Google from experimenting with alternatives. The Register found that Google recently carried out an experiment to port Blink to iOS, but the Chromium team emphasized that this was only to test display and input performance, not to develop a “shelf-ready product.” Google also stated in a statement that this is only a “test prototype” in its open source program and will not be open to the public in the future, and Google will “continue to abide by” Apple’s rules.
If Apple is so strict, why is Google testing Blink? One possibility is that the U.S. government is pushing Apple and Google to open up their respective platforms, giving users the option to install software themselves, bypassing both app stores. At the same time, there are also rumors that Apple may open the installation of third-party app stores on Apple machines in order to meet the requirements of the European Union. If any of these things come true, Google will be able to justifiably launch Chrome using the Blink rendering engine, so the experiment at this point will work.
Currently, since all browsers on iOS use the same engine, performance and rendered web pages are consistent. Different browsers can only be differentiated by interface design and some functions that have nothing to do with webpage rendering.