You need to wait for a firmware update to your phone and then accept Extras+info app update. The extras+info app update installs the Storage Check app to the Lumia device. It will be visible in the Settings menu.
- How long does it take to start up the phone for the first time?
- What can I do to free up the phone memory on my Lumia?
- What is visual voicemail and how do I switch it on?
- What is the Windows Phone Find My Phone functionality, and how does that work?
- How do I resize the tiles on the start screen of the Nokia Lumia to a different size?