The list of devices confirms that only those using Nexus devices that were launched in the past two years can download and try out Android N beta on their devices. However, the final version of Android N that will launch later in the summer with Google's upcoming Nexus devices will be a lot better than the beta version and will carry far fewer bugs.
Current Nexus devices won't get seamless Android N updates
While Android N has undoubtedly brought in a number of new features, security updates and battery saving functions compared to Android 6.0 Marshmallow, you will be able to try out these features and provide feedback to Google based on your experiences. Once you download the beta version, you can try out a new app carousel which will put recently used apps in a list, use two screens at a time, try out the 'Clear All' button, respond to notifications without opening apps as well as try out the new Unicode 9 emoji support.
However, Android N also brings in a exciting new feature called Seamless Updates but you will not be able to use it on your Nexus device. Seamless Updates will let all OS updates download and install themselves on the background while you're busy with your phone and will do away with the manual updating process. Sadly, Seamless Updates will only work on Android phones which will come with Android N pre-loaded.
Google's Allo and Duo to challenge WhatsApp and Skype
Android N is based on a lower GPU overhead and a new graphics API named Vulcan. Thanks to these additions, apps will install 75 per cent faster in phones running Android N compared to those that run older operating systems, including Marshmallow. The new operating system also includes file-based encryption, media-hardening framework, new battery saving features and probably a lot of good-looking wallpapers. If you're interested, you can download the beta version at https://g.co/androidbeta but you will need to sign up first. If you would like to know more about Android N before installing it, you can read about it on Google's developer website.