What is the one feature(new) that you found like totally cool in Windows 10 tech preview(mobile)?

[Aravinth Aravi]

I haven't tested Windows 10 mobile (tech preview) yet... But I like to know about Windows 10. So guys tell which feature is awesome in windows 10 mobile(no matter how big or small). But I don't want things like android and ios app porting(Because those things are not what i would call a cool feature). Eagerly waiting for your answers and thanks for reading my question