In China, since around 2015, smartwatches have become widely used by schoolchildren. They are advertised on television throughout the country as a safety device whereby the child can call in case of emergency. The devices are commonly colorful and made of plastic. They normally have no display unless a button is pushed. These smartwatches have limited capability compared to other smartwatches; their main functions consist of being able to conduct calls, displaying of time, and sometimes have air temperature sensitivity. They cost around $100 to $200 USD.
The Martian Passport wants to give you the best of both watch worlds, by offering a mechanical, analog watch face and a small LCD. If you prefer a traditional-looking watch and want the “smart” component to be unobtrusive, this model may work for you. It comes in three varieties, all with silver bezels: a white face with a black or white band or a black face with a black band.
The Series 4 now has several new health-focused features, which are very intriguing, including the ability to detect when you fall and even alert emergency contacts if need be, as well as an electrical heart rate sensor that works with an app to alert you to heart health issues. The electrocardiogram (ECG) app has been certified by the Food & Drug Administration, but it's not out yet.
The top smartwatches that debuted at the 2017 Consumer Electronics Show included the Casio WSD-F20, Misfit Wearables Vapor and the Garmin Fenix 5 series. Apple released on September 22, 2017 their Apple Watch Series 3 model which offers built in LTE cellular connectivity allowing phone calls, messaging and data without relying on a nearby smartphone connection. 
The Apple Watch Series 3 is a really nice smartwatch that does exactly what it should. This is easily one of the best smartwatches on the market. It’ll give you quick access to notifications, allow you to pay with your wrist, give you turn-by-turn directions, and it’s a decent fitness tracker. In terms of design, it doesn’t feel like Apple cut too many corners with the overall look and feel of the device. Even the Sport model (the cheapest one of the bunch) feels like a well-built piece of hardware.
The Galaxy Watch comes in two sizes, 46mm and 42mm, both with an OLED display and an “optimized” chipset that extends battery life. For the larger model, you can squeeze 6 days out of a single charge while the smaller model still offers up to 4 days. As you’d expect, the Watch also includes features like GPS, water resistance, and there’s NFC for Samsung Pay.
Garmin, known primarily for its GPS and fitness devices, has taken one step closer to full-featured smartwatches with their Vivoactive 3 Music. This model doesn't run on Wear OS (Google's increasingly-popular OS for wearables), but it does offer thousands of free apps, watch faces, and more via Garmin’s ConnectIQ store. The Vivoactive 3 Music also comes preloaded with 15 sports apps to monitor your progress whether you're running, swimming, lifting, or doing yoga — because, at its core, Garmin is still all about fitness tracking
The Nixon Mission is a rugged 'action' smartwatch, and we really like it. The durable casing can take a bashing, while the Qualcomm Snapdragon Wear 2100 keeps things ticking inside. It runs Android Wear, but also comes with some useful pre-installed apps which track real-time surfing and snowboarding conditions. It's water resistant to 10ATM (roughly 100m), and best of all, it comes in Orange.
Apple Watch is crisp, beautiful, high-resolution screen that’s smaller than an Oreo cookie. No surprise, Apple knows what they’re doing when they design a home product. Much like the other additions to the Apple suite, the Series 3 is sleek and stylish. Everything from the navigation to the screen layouts has been optimized to utilize the space given rather than be constricted by it.
Bottom line: Some fitness trackers work equally well with an iPhone or Android device, but some smartwatches are built to pair with Android phones so you won’t enjoy full functionality and pairing on an iPhone. The Apple Watch only pairs with the iPhone so is off limits to Android users. Your existing phone choice will play an important part in choosing a smartwatch. You can check your smartphone’s compatibility with a range of Google Wear-powered smartwatches at g.co/WearCheck
The Huawei Watch 2 comes into its own if you’re looking for a smartwatch that can double as a sports watch, thanks to built-in GPS and a heart rate monitor on its rear. Use the 4GB of built-in storage to save your Google Play Music playlists offline and you can pair Bluetooth headphones for a phone-free experience. The Huawei Watch 2 will work with Huawei’s own suite of fitness apps, Google Fit, or other third-party apps such as Strava, offering excellent choice.
The Samsung Gear Live is the first of the company’s smartwatches to be compatible with any Android phone running Android 4.3 or higher; other Gear models can be paired only with specific Samsung phones. Like the LG G Watch and Moto 360, it runs the Android Wear OS, allowing voice commands and pushing relevant information to the wearer. Compared with the LG G Watch, we prefer the style and fit of the Gear Live. The watch body is slightly curved, which made it more comfortable. The Gear Live also has a heart-rate monitor, which the G Watch lacks.
In order to find the best smart watch, we looked at text and call features and, of course, design. We dug into tech reviews to separate must-haves from perks. Then, we brought in 19 smart watches to test for call responsiveness, text-ability, app accessibility, and general ease of us. In the end, three watches stood out for their reliable connectivity, gorgeous interfaces, and easy navigation.