No, you&#x27;re not locked in to using the default Mail app anymore. Since iOS 8, mail app developers can write a share sheet extension and you can access their mailer wherever you can access system share sheets.<p>And you&#x27;re not really stuck with Xcode anymore than you&#x27;re stuck with Visual Studio on Windows. You can use the command line tools to do everything yourself, it&#x27;s just more difficult. You can also obviously write apps in Java or even Electron, which is very popular these days.<p>As for Siri not using your custom music player, that&#x27;s unfortunate. But integration often comes at the cost of extensibility, and while Apple has the former nailed, they are still clearly working on the latter.