The operating system you choose depends solely on the type of smartphone you have because the smart watch is paired with your smartphone. If you own an Android smartphone, your smart watch should have Android Wear or Tizen. If you own an iPhone, choose an Apple Watch. For example, the Samsung Gear S3 runs Tizen and is compatible with both the Android and iPhone.
As of July 2013, the list of companies that were engaged in smartwatch development activities consists of Acer, Apple, BlackBerry, Foxconn/Hon Hai, Google, LG, Microsoft, Qualcomm, Samsung, Sony, VESAG and Toshiba. Some notable omissions from this list include HP, HTC, Lenovo, and Nokia.[59] Science and technology journalist Christopher Mims identified the following points in relation to the future of smartwatches:
"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.

While testing the Q Venture, we found the response time to be pretty solid when it came to calls and notifications. The typical response time for a notification was somewhere around 10 seconds. We were, however, able to immediately ignore calls. This quick response time should give you plenty of time to retrieve your phone from your pocket or fish it out of your purse.

Like other Fitbit devices, the Charge 3 takes little effort to set up. It works with Android and iOS devices, and all you need is the Fitbit mobile app to use it. Choose the Charge 3 from the list of devices you can pair via Bluetooth to your smartphone or tablet, and follow the on-screen instructions. After setup, you may want to also edit basic information that the Charge 3 uses when tracking activity, such as your age, height, weight, and the activity metric you care most about (steps, active minutes, etc).

Google confirmed to Tom's Guide that the company won't be releasing its own Wear OS smartwatch this year. The news comes after months of rumors that a Google-branded Pixel Watch running on Qualcomm's latest processor would be launched at Google's October hardware event. Instead, Google plans to focus on adding features to Wear OS on the software side and support the companies who are currently making Android smartwatches. Google's hardware event is Oct. 9.
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