Read original post by Karl Ots at Fincooper
In Windows 8 development, there are some differences between the Javascript and XAML APIs. Some things are available in JS but not in XAML and vice versa. One example is the SettingsFlyout control. There is no SettingsFlyout control for creating a settings menu item in XAML, although that exists in JS. The de facto solution is to create your own custom page and show/dismiss it according to the settings charm events. As this is something that basically every Metro app (or “Windows 8 style application“) has to include, it’s fortunate that there’s now a bit less tiresome way of doing this.