The update is supposed to bring a host of improvements and new features to the existing WP8 Lumia phones, however, the Lumia 925 happens to already ship with the updated version of the OS.
The tweet was sent out by the official Twitter account of Nokia Spain and can be found below (in Spanish):
Roughly, it translates to “The Amber update for Nokia Lumia range with WP8 arrive in August giving the same user experience as #Lumia925” (yes, we used Google Translator). The update is supposed to bring a new Lockscreen to all WP8 devices which would display the clock, battery status and the ringer volume on the screen even in stand-by mode.
Along with that, there will be a “double-tap to unlock” mode. Probably the most notable feature, however, will be the enabling of the FM radio chip that has been lying dormant in all Lumia (WP8 only) phones, except the Lumia 620.