With the second preview happened last month, Google was so fast on releasing the final preview as it was expected to come only after a month or two. This also mean that we get to have a look at the final build and looks of the new OS.
This early release helps devs to build apps quickly for Android O and device variants for Pixel and Nexus, which showcase the Android O firstly will witness many new apps interfaced for Android O's features.
As of now, the developer preview is available for free download but a beta version will be released soon for Pixel versions like Pixel XL, Pixel, Pixel C and Nexus devices like Nexus 6P, Nexus 5X, and Nexus Player.
