Why Apple Watch looks more promising

Apple CEO Tim Cook speaks about the Apple Watch during an Apple event at the Flint Center in Cupertino, California, September 9, 2014. Cook is expected to make the case for why it's a must-have gadget at a San Francisco event later on Monday.

In September, Apple said several apps are in development. One would open your room at Starwood hotels. Another would help you find your BMW in a crowded parking lot. It's not yet known what apps will be rolled out with the April launch. But the success of Apple Watch could ride on what apps are in store to extend the watch's functionality.

The watch likely will need to be recharged nightly, just like the phone. Some fitness trackers can last for days without a recharge, but full-featured smartwatches typically last a day or two at most. What's not known is how well Apple Watch will be able to last even a full day under heavy use.

Apple has said the watch will start at $349 for the base model. There will be three different lines: aluminum for fitness enthusiasts, stainless steel for everyday wear and luxury 18-karat gold. Each line will come in two sizes and offer a variety of wristbands. The luxury edition might cost several thousand dollars, in line with other high-end jewelry.

Apple will likely give a specific release date on Monday, along with a list of initial markets outside the U.S.