Sony's not new to the wearable market, but the company just entered the fitness-tracking market in a big way — during its CES press conference, the company announced Core. It's a tiny chip that Sony called perhaps the tiniest gadget it has ever made, and the company's planning to put it into a number of products, starting with a smartband that'll be released this spring. Core will include the typical fitness-tracking metrics, but Sony says it'll also function as more of a life journal as well, tracking photos you took, "special moments," and other live events — kind of like the Day One journaling app with a fitness tracker.

Absurdly light and tiny

Sony admits the details are vague, but the company is currently working with hardware partners to embed the Core technology into other hardware makers. Given that Sony Mobile CEO Kuni Suzuki introduced the Core, we're expecting to see it integrated into Sony's Xperia line of smartphones before long, as well.

We got a chance to check out the hardware at Sony's booth, and it's absurdly tiny and light. Sony says the battery life is about five days on a single charge. That's not too surprising since the only display on it are three tiny LED lights that go on when you click its one button. But there's also a vibration motor that will alert you when you're getting a call, and let you click to mute your connected smartphone. The button also pulls double duty for what Sony calls a "life bookmark," something you tap to mark that particular point in the day to refer back to later in the companion smartphone app.

We were able to spend some time with Sony's Lifelog app as well, and were impressed by the approach. It's a very visual design, that allows the user to slide back and forth across their personal history on a side-scrolling timeline. Weather is recorded, and if it's set to rain the following day you'll see the weather condition when you scroll forward to the next morning. It also logs the media you watch, so if you spend a night kicked back watching a movie on your device it will log that info as well. The same principle applies to exercise tracking, as well; if you scroll down through a jog, it will map your route while including the songs you listened to on your run.

The Core will be shipping to both Europe and the US for 99 Euros (Sony did not provide a US price) in the first quarter of this year. Sony will also be selling a pack of three extra colorful bands you can stuff the Core into for somewhere between 15 to 20 Euros, though Sony told us they hadn't settled on a price yet.

Josh Lowensohn and Bryan Bishop contributed to this report.