The only way to use WordPress in an app is with a webview, it is not possible any other way. We are aware of Apple's guidelines for apps, but webviews are standard in many apps, including those designed by Apple (such as the Apple store app).
The webview itself is not the problem, it's when people try to make apps that don't need to be apps. Wrapping a normal, non-interactive site in an app is an example of something that will be rejected.
The purpose of AppPresser is to create interactive, useful apps using native device features, not to wrap a normal website into an app. We have approved apps in the Apple and Android stores already, so we know there is not a problem with this method.
I hope that helps :)