The ‘Lumia Denim’ adds functionality exclusively to Lumia phones running Windows Phone 8 which significant improvements to the Lumia 830, Lumia 930 and Lumia 1520 smartphones.

The flagship 830 will come with Windows Phone 8.1 with Lumia Denim operating system, 1 GB RAM, 16 GB internal user memory (15 GB OneDrive cloud storage and up to 128 GB micro SD card). It has a 5-inch display, 1.2 GHz quad-core processor, 10 MP camera and 2,200 mAh removable battery.

Lumia 930 sports a 20-megapixel PureView rear camera and 1.2-megapixel front camera. It is powered by a 2.2 GHz quad-core Qualcomm Snapdragon 800 processor coupled with 2GB of RAM. The smartphone runs on Windows Phone 8.1 operating system, which includes Microsoft's new personal assistant Cortana.

It is installed with a 5-inch ClearBlack OLED display that possesses a full-HD resolution of 1920 x 1080 pixels at a density of 441ppi. The company claims that the phone can shoot as well as record in HD mode. It is loaded with a 2420 mAh battery with inbuilt wireless charging capabilities.

The Nokia Lumia 1520 is a 6-inch Lumia smartphone and based on Windows Phone 8 operating system with a 20 megapixel camera. It comes with 2GB RAM and 32 GB internal user memory.

Go to Settings > Phone Update > Check for Updates to see whether Lumia Denim is available for your smartphone.