The technology giant is hoping to make Watch, a device that displays emails, tracks fitness activity and, of course, tells time, into a yet another blockbuster product in line with the iPhone and iPad. Executives will reveal more details about its capabilities on Monday in prelude to Watch going on sale in April (Check out Fortune’s coverage of the event starting at 1 p,m. EST).

But Apple (AAPL) is hardly alone in pushing smartwatches. A number of manufacturers are also trying to solve the riddle – to varying degrees of success. Some of their devices look so clunky that few people would be caught dead wearing in them in public. Others are clumsy to use and offer little in the way of compelling features. Virtually all are poor substitutes for the smartphone, which have big enough screens to handle most basic online chores while small enough for people to conveniently carry in their pockets.

Still, smartwatches may be useful or intriguing to buy, particularly for those who like to be on the cutting edge. Here are a few options that, unlike Apple’s Watch, are already on sale. But warning: Many manufacturers plan to update their smartwatches in the next few months.

Moto 360

In the latest generation of smartwatches, the Motorola's Moto 360 is among the most compelling. Unlike many of its competitors, the watch was designed with aesthetics in mind so it doesn't look like a mini-radio glued to the wrist. It has a relatively attractive round steel frame, a leather strap, and a clock display that can be set to eight different faces. In terms of features, the watch tracks heart rate and acts as a pedometer. When paired with a phone via Bluetooth, it can provide vibrating alerts when new emails and Facebook friend requests arrive. The operating system, Android Wear, also culls information from Gmail, calendar and other sources for more intuitive alerts. For example, you can get a heads up if you risk being late for a doctor's appointment because of highway gridlock. Price: $250

Pebble Steel

Pebble's Steel is a smartwatch without smartphone envy. The watch has a retro feel without flashy graphics or touch screen controls. To scroll up and down, users must press tiny buttons on the side of the watch - a clumsy maneuver for people with big fingers. Information shown on the screen is purely functional and displayed in black and white only. You can forget about surfing the web at-large. A large library of apps handles chores like tracking temperature, sleep and distance run or walked. Users who pair the watch with their phone can get buzzed when new emails arrive or when they get a phone call.  The design isn't exactly handsome. But it does the job with a relatively unobtrusive and compact body compared to some competition. Compatible with both Android phones and Apple iOS. Price: $200

Samsung Gear 2

Of all smartwatch makers, Samsung has had the most success finding buyers, according to analysts. But the achievement is relative: At this stage, it doesn't take much to be at the top of the list. Still, Samsung has made an aggressive push with its line of smartwatches. The Gear 2 is the best-known among them. The watch tries mightily to be indispensable. Along with buzzing when new emails arrive, tracking distances, monitoring heart rate, the device lets users take photos (if they don't mind twisting their wrist just-so to line up the lens), play music, make calls via speaker phone, and play games. A big downside is that the watch only pairs with Samsung phones via Bluetooth, severely limiting the universe of people who can use Gear 2. Price: $300