HDX is a remarkably powerful tablet duo, but as ever it's Amazon's software (a forked version of Android 4.2) that powers the device. There's a new version of Fire OS, 3.0, called "Mojito," coming out alongside the Fire HDX, which brings a lot of both Amazon-specific features and things any tablet user would need.

First and foremost, the carousel is no longer mandatory — there’s a grid view for all your content if spinning a wheel isn’t your thing. The email, calendar, and document-editing apps are hugely improved, and they're far more usable than ever. If you’ve been holding off on a Fire because of a bad Gmail experience, this could change things for you. Amazon has added desperately needed features like threaded messaging support and label management to its email repertoire. There's a lot more enterprise support for the business user, new tools for visually impaired users, and more.

But Amazon's tablets are for doing Amazon things, and there are plenty more to do with the HDX. Of course, there’s access to Amazon’s huge list of Kindle content, from books to movies to the small-but-growing Amazon Appstore. Most of that is available to any Kindle Fire owner, but there’s one new perk here: you can now download Prime Instant Videos and watch them offline, which essentially gives HDX owners the biggest DVD collection on the planet. (New Fire HDX models come with a month of Prime, for the uninitiated.)

X-Ray is otherwise the dominant new feature here. X-Ray for music adds auto-scrolling lyrics to the song you’re listening to, and will even identify the song that’s playing in the show or movie you’re watching. It’ll give you trivia for whatever you’re watching, backstories for the characters, and all the other information Amazon-owned IMDb can provide.

The Kindle Fire HDX plays nice with your TV

If it all sounds a little like the Xbox SmartGlass second-screen companion, you’re not far off. Amazon’s built essentially the same service, down to the second-screen piece: if you have a PlayStation 3 (or 4, soon) or a Samsung TV, you can send TV and movies straight from your tablet to your TV and then see added information or playback controls on the tablet itself. If you can get Miracast working on your TV there’s a mirroring feature as well. It’s all done through the Second Screen app — good app, but the name needs work.

There’s plenty of under-the-hood enhancement in Mojito as well. Reading Mode powers down most of the OS when all you’re doing is turning pages (that’s how you get 17 hours of battery), and there’s a Quiet Time switch for when you don’t want your notifications luring you away from your book. The OS can even now redirect all its attention to whatever you’re doing, in an attempt to make page-turning or swiping faster and more responsive.

Amazon’s most innovative (and maybe most controversial) feature is probably Mayday, the virtual genius bar the company has enabled for HDX owners. If you’re having a problem, just tap the Mayday button in your settings, and within 15 seconds an actual human will appear on your screen, with full control of your device. They can walk you through how to do something, or figure out what’s broken. And they don’t have to explain to you what the button looks like, they can just draw you diagrams or show you themselves. Right on your screen.