Nokia has started rolling out its Lumia Black update for the Lumia 520, which build on Windows Phone GDR3 and adds support for closing apps from the multitasking UI, auto-rotation lock and support for Bluetooth LE. Nokia Drive and Nokia Storyteller are also supported, but it doesn't get Nokia Beamer and Refocus apps which require atleast 1 GB RAM. Although Nokia Camera app with Pro features is available.
You can check if the update is available by going into Settings and then Phone Update.
