Lumia Cyan is the third firmware update from Nokia's mobile division, now owned by Microsoft. Lumia Cyan is distributed in parallel with the Windows Phone 8.1 OS update, and provides the necessary drivers and APIs for specific Lumia devices. As such, it enables unique Lumia features like the PureView camera, Living Images and an updated Creative Studio editing app, in addition to optimizing the battery, performance, Bluetooth 4.0 LE, a revised Camera app and general telephony functions.

Other features of the Lumia Cyan update will be dependent upon specific hardware. For example, the Lumia 930, Lumia Icon, and Lumia 1520 are expected to receive SensorCore support for a built in pedometer and exercise features. Those three phones will also have new camera algorithms applied to improve the quality of photos.

Miracast support for select devices will also be facilitated with the Lumia Cyan update, allowing users to stream media and mirror their phones on Miracast compliant devices, like TVs and computers.

Lumia Cyan will let users set the ranges for brightness levels. For example, you can have your 'low' setting very low, or make the 'High' setting less intense.

Nokia Treasure Tag support will come with Lumia Cyan due to the inclusion of a revamped Bluetooth 4.0 LE stack. (Early adopters of the Windows Phone 8.1 Preview for Developers had Bluetooth 4.0 LE removed due to incompatibility issues).

Dolby Digital Plus recording ability, the first of its kind in mobile, is anticipated to be enabled in the Lumia 930, Lumia Icon and Lumia 1520, once again due to their unique hardware with newer Qualcomm chipsets.

The Lumia Cyan firmware update and Windows Phone 8.1 OS refresh began to roll-out over-the-air on June 25th, 2014, but only for the Lumia 925 in Finland and also in Argentina. The update will arrive for other phones throughout June, July and August, depending on the Lumia model, carrier (if applicable) and country/region.

Prior to Lumia Cyan, Nokia had released Lumia Black and Amber firmware, corresponding with Windows Phone 8.0 Update 3 and Windows Phone 8 Update 2 refreshes.

• Track the Lumia Cyan update releases so far on our tracker page here.