Samsung has announced its worst kept secret, but nonetheless exciting Galaxy S4. Revealed at tonight's Unpacked event in New York City, the Galaxy S4 will take the mantle of the Galaxy S III as Samsung's new flagship smartphone, sporting a massive 5-inch 1080p Super AMOLED display with a pixel density of 441ppi — a significant leap over the Galaxy S III's 306ppi display and the iPhone 5's 326ppi retina display. While similar to last year's model, the design has undergone some notable upgrades, including a thinner bezel around the new display and sleek metal trim around the sides.

But perhaps the most exciting new features, however, are Samsung's suite of user-tracking functions, including its new Smart Pause, Air View, and floating touch controls. The Galaxy S4 uses its front-facing camera to detect when a user looks away from the video they're watching and automatically pauses playback. Air View, on the other hand, allows users to scroll through pages with a wave of their hand. Floating touch takes Samsung's S Pen concept and applies it to your fingers, allowing you to point and hover over an item to view it.

Samsung has also made vast improvements to its camera technology. The Galaxy S4 has a built-in 13-megapixel camera, up from the Galaxy S III's 8-megapixel sensor, which uses new camera functions Dual Shot, Eraser, Drama Shot, and Sound & Shot. Dual Shot allows you to capture images from both the front and rear cameras simultaneously, while Eraser captures multiple frames so that you can remove unwanted subjects, Drama Shot composites moving objects for action shots, and Sound & Shot captures five seconds of images and audio before the capture button is pressed, not unlike HTC's Zoe technology.

The phone runs Android 4.2.2 Jelly Bean, but Samsung has developed a suite of its own new software as well. For one, the GS4 will ship with a photo album publishing service, like Apple's greeting card service, which allows you to design a custom photo album directly from your phone that will be shipped to your home. What's more, the Galaxy S4 ships with S Translate, a baked-in realtime translator that supports 9 different languages, while S Voice Drive improves GPS driving capabilities. It also sports a built-in IR transmitter for controlling your TV and other devices in your entertainment center.

The Galaxy S4 is powered by Samsung's Exynos 5 Octa processor, which was introduced at CES in January as the 'world's first' 8-core mobile processor. Models in certain regions, however, will ship with only a quad-core processor. It comes with 2GB of RAM — double that of the iPhone 5 —and 16GB, 32GB, or 64GB of on-board storage. The Galaxy S4 comes with a large, 2,600mAh battery, roughly 23-percent larger than the Galaxy S III. It's also three grams lighter and a millimeter thinner.

The Galaxy S4 will ship in April on 327 carriers in 155 countries in both 4G LTE and 3G versions. In the U.S. it will be offered on Sprint, Verizon, AT&T, T-Mobile, and others.