Android 4.4 KitKat landed on Halloween with a bag full of treats, including a refreshed user interface, new features, better integration with Google’s apps and services, and a slew of improvements under the hood.

While there are plenty of sources online where you can get up to speed with Google’s latest and greatest operating system, sometimes it’s better to go right to the source. For those of you who can’t get enough of KitKat, that source is Google’s own Android Quick Start Guide, Android 4.4 (KitKat), now available for free in the Play Store.

For some reason, the 53-page user guide is currently available in the United States only, though we expect Google to lift this curious restriction in the future. The Nexus 5 is selling in ten countries through the Play Store, and is going to become available from more retailers and carriers from around the world in the coming weeks.

Another requirement to read the guide is that you have Google Play Books installed, but that shouldn’t be a problem for most users.

Update: here’s the Android Quick Start Guide, Android 4.4 (KitKat) online in a PDF version.

Android Quick Start Guide, Android 4.4 (KitKat)

In case you can’t download the user guide, Google’s offers a rundown of Android 4.4 on its developers site, while our own Chris Smith went through the top features of KitKat here.