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.
Waterproof to 165 feet and tested to military standards for durability, it includes features like a digital compass, altimeter, and barometer that you won’t find in most other smartwatches, as well as more standard tools such as GPS. The WSD-F20 can also function as a flashlight — handy in an emergency — and lets you download maps for offline navigation when you’re far from the nearest cell signal.
"Sport watch" functionality often includes activity tracker features (also known as "fitness tracker") as seen in GPS watches made for training, diving, and outdoor sports. Functions may include training programs (such as intervals), lap times, speed display, GPS tracking unit, Route tracking, dive computer, heart rate monitor compatibility, Cadence sensor compatibility, and compatibility with sport transitions (as in triathlons). Other watches can cooperate with an app in a smartphone to carry out their functions. They are paired usually by Bluetooth with a smartphone. Some of these only work with a phone that runs the same mobile operating system; others use a unique watch OS, or otherwise are able to work with most smartphones. Paired, the watch may function as a remote to the phone. This allows the watch to display data such as calls, SMS messages, emails, calendar invites, and any data that may be made available by relevant phone apps. Some fitness tracker watches give users reports on the number of kilometers they walked, hours they slept, and so on.
I visited the Fitbit app more than I usually do during the first day of wearing the Charge 3 so I could manage notifications. This device is the first tracker to go beyond the basic call, text, and calendar alerts that most Fitbit trackers can receive. The Charge 3 can alert you to any and all happenings on your smartphone if you want. In the notification panel in the Fitbit app, you can choose which apps you want to receive alerts from—turn on all of them so you never miss a beat, or only turn on the apps that are most important to you.
Although rectangular is the most common design, there are smart watches that have a circular display similar to regular watches. The Apple Watch is only available in the rectangular design. The circular design is available in the Samsung Gear S2, Moto 360, and LG G Watch R models. Many models have changeable straps, so you can dress casual, sporty, and formal.
In 1998, Steve Mann invented, designed, and built the world's first Linux wristwatch,[15] which he presented at IEEE ISSCC2000 on 7 February 2000, where he was named "the father of wearable computing".[16] See also Linux Journal,[17] where Mann's Linux wristwatch appeared on the cover and was the feature article of LJ Issue 75. Seiko launched the Ruputer in Japan - a wristwatch computer with a 3.6 MHz processor. It was not very successful, since instead of a touchscreen it used a joystick-like device to input characters (much like high scores in arcade games), and the small screen with a resolution at 102x64 in 4 greyscales made it hard to read large amounts of text. Outside of Japan, this watch was distributed as the Matsucom onHand PC. Despite the rather low demand, the Matsucom onHand PC was distributed until 2006, making it a smartwatch with a rather long life cycle. Ruputer and onHand PC applications are 100% compatible. This watch is sometimes considered the first smartwatch since it was the first watch to offer graphics display (albeit monochrome) and many 3rd party applications (mostly homebrew).

No other smartwatch offers this much variety and customization, especially when it comes to female-friendly options. The Apple Watch is the only smartwatch I've ever worn regularly each day for months on end. I've reviewed dozens of WearOS watches, and although many of them are nice looking as well, they're not as fully featured or easy to use as the Apple Watch.
The first digital watch, which debuted in 1972, was the Pulsar manufactured by Hamilton Watch Company. "Pulsar" became a brand name which would later be acquired by Seiko in 1978. In 1982, a Pulsar watch (NL C01) was released which could store 24 digits, making it most likely the first watch with user-programmable memory, or "memorybank" watch.[9] With the introduction of personal computers in the 1980s, Seiko began to develop computers in the form of watches. The Data 2000 watch (1983) came with an external keyboard for data-entry. Data was synced from the keyboard to the watch via electro-magnetic coupling (wireless docking). The name comes from its ability to store 2000 characters. The D409 was the first Seiko model with on-board data entry (via a miniature keyboard) and featured a dot matrix display.[10] Its memory was tiny, at only 112 digits.[9] It was released in 1984, in gold, silver and black.[11] These models were followed by many others by Seiko during the 1980s, most notably the "RC Series": During the 1980s, Casio began to market a successful line of "computer watches", in addition to its calculator watches. Most notable was the Casio data bank series. Novelty "game watches", such as the Nelsonic game watches, were also produced by Casio and other companies.[citation needed]
The Gear 2 also includes a gyroscope, an accelerometer, and a heart-rate sensor. It also can control a TV or set-top box remotely using a built-in IR blaster, and it has the ability to function as a stand-alone music player. And its built-in camera—handily built into the watch itself rather than on the band, like the original Galaxy Gear—takes 2-megapixel stills and 720p video.
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.