Along with a handful of new tablets, Amazon has officially announced Fire OS 4 (codenamed Sangria), which it says adds hundreds of new features to the "content-forward" operating system.

First and foremost, Amazon says the user interface in Fire OS has gotten a facelift. Amazon hasn't gone into detail in describing its UI changes, but visual tweaks are certainly welcome to an interface that can at times seem scattered.

Besides that, Amazon is touting new features like ASAP, Smart Suspend, and the addition of individual user profiles to make for easier sharing among families.

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