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Wear OS Application Development Tutorial. Part 1


7 min read

Mobile devices have become part of our everyday lives long ago; however, they have evolved greatly in the last decade to take on the majority of their owners’ responsibilities and simplify their life to the utmost. Around forty-one percent of US citizens have wearables, whereas global end-user spending on such gadgets is expected to reach 63 billion dollars by 2021, with smartwatches being one of those leading the market growth.

Smartwatches’ popularity is easy to explain if we look at the range of functions they provide that reach far beyond displaying the time as their mechanical counterparts do. They are very compact, yet let you perform dozens of actions, like checking notifications, messaging, replying to calls, playing music, watching videos, tracking your activity, executing payments, and many others. Thus, a smartwatch represents an all-in-one technological assistant, replacing a fitness tracker, wallet, and even a phone.

The use of the mentioned solution significantly improves life quality by sparing its users’ unnecessary movements. With a watch always in sight, you can get all the information by taking a look at your wrist. Thus, you’re unlikely to miss an important call or message or, on the contrary, know when there is nothing worth bothering yourself with getting the phone out of pocket or bag, which can be a real help in a stuffed public transport.

The Way It Works

Smartwatches are digital machines based on various mobile OSs that are worn on the wrist and equipped with a touchscreen interface, enabling actions performance by tapping or swiping on it. They can serve as standalone devices or rely on smartphones to broaden their functionality. In the latter case, data is first received by the phone and then sent to the watch via Bluetooth. Besides, smartwatches come with built-in sensors providing for the tracking function used in health, fitness, GPS, and other applications. Apart from embedded tools, the feature scope of watches can be expanded through the installation of third-party apps.

Best Smartwatch Features

The functionality of smartwatches depends on the manufacturer, model, and issue date. The newer the watch, the greater variety of features a user can enjoy, and the better are its overall characteristics, like operation time or speed. Here’s a list of functions smartwatches commonly perform:

  1. Duplicating phone notifications. Read, open, and even reply to messages forwarded to your phone and displayed on the watch using your voice or on-screen mini-keyboard. The solution gives the possibility to review SMS, calendar alarms, apps, and social media notifications.
  2. Tracking physical activity. Watches allow calculating all the critical metrics to achieve your fitness goals: they count heart & pulse rate, steps, distance, calories, sleep, and anything else that matters to you. Calorie burn and food tracking apps for weight loss are the most popular ones, accounting for forty-one percent of US smartwatch owners, mainly used for logging the amount and type of food eaten.
  3. Determining user location. You will no longer get lost, as the smartwatch with a built-in GPS sensor or the one receiving data from a smartphone synchronized with it can help identify where you are. Moreover, the device serves as a guide, sending directions to follow and location-specific alerts.
  4. Accepting/declining calls. A smartwatch that answers calls is already a reality, while the functionality range depends on a particular model. For example, Apple Watch has a speaker and microphone, enabling chatting without taking your iPhone out of your bag or pocket. At the same time, many other wearables require a Bluetooth headset for communication. Standalone smartwatches have a separate Sim card slot, while the latest devices support eSIM technology with a mobile operator code embedded into a watch.
  5. Ensuring kids’ safety. The GPS tracker can show a child’s location, while the geofencing feature presets safe zones to roam within. Some watches allow kids to send voice memos and SOS signals to their parents’ phones with a tap. Moreover, a parent receives an alert when the watch is taken off.
  6. Managing music players. You can control the music playing on the phone, switch songs, adjust the volume, or create a separate music library in the smartwatch storage. Google Play Music and Spotify are some of the best apps available that let you play music right from the watch with no need for a phone connection.
  7. Finding your phone. Pairing the mobile with a watch will help locate it when it’s out of sight. Press a few buttons on the smartwatch, and the phone will ring. Nonetheless, the sensor range is limited, making this feature relevant within the house.
  8. Executing contactless payments. Many smartwatches have an embedded NFC chip that provides encrypted data exchange between readers and payment devices at a distance of about two inches. Thus, users need neither a plastic card nor a phone to make a purchase.

In addition to the described functions, the smartwatch provides access to the calculator, alarm clock, stopwatch, timer, and allows playing videos. There’re even devices incorporating medical alert systems with fall detection. The list is far from exhaustive, as every brand strives to create a unique product, adding more and more sophisticated features. Given all that, the lucky owners of the latest smartwatch models are empowered to perform a multitude of actions, and, provided they make use of third-party apps, there is hardly anything a smartwatch is incapable of dealing with.

Smartwatch Manufacturers, Operating Systems & Compatibility with Mobile Phones

Nowadays, the smartwatch market is pretty competitive, with multiple models based on different OSs available. The leading operating systems include watchOS, Tizen, Wear OS, and Fitbit, which are compatible with multiple smartphones:

  • watchOS is based on the iOS mobile operating system running on iPhones and is installed exclusively on the Apple Watch, which has been an absolute leader among smartwatches since its debut in 2014. As for now, it holds 47.9 percent of the global smartwatch market share, and its shipments are expected to reach 46.9 million units by 2022. Apple Watch can be paired only with the mobile phone of the same brand, complementing it to the fullest, which makes the choice of a smartwatch easy for iPhone users. The fifth generation of the watch coming pre-installed with watchOS 6 requires an iPhone 6s or later running iOS 13 or higher.
  • Tizen is developed by Samsung and works best with the phones by this manufacturer, but these OS-based watches are compatible with other Android mobiles and iPhones. Tizen’s market share amounts to 13.4 percent, making it the second-largest smartwatch distributor worldwide. Some Tizen OS smartwatch models, like Gear 1, Gear 2, Gear S, or Gear Fit, can pair only with Samsung devices. Nonetheless, most smartwatches running this operating system also go well with phones having Android 5.0 or higher with 1.5GB RAM and iPhones later than the iPhone 5 using iOS 9 or higher.
  • Fitbit OS underlies smartwatches produced by Fitbit, a manufacturer specialized in wearables for the health and fitness industry and producing top physical activity tracking devices. Thus, the primary functions of its watches include counting steps, distance, active minutes, calories, sleep tracking, monitoring heart rate, and providing other valuable body-related metrics, making it quite the best smartwatch for working out. However, what distinguishes it from an ordinary activity tracker and makes a smartwatch is its communicative features, enabling you to use a smart voice assistant, review and reply to messages and notifications, accept and reject calls. Fitbit products work with Apple devices that support iOS 11 and higher and Androids with OS 7.0 or higher. In February 2020, there were 50.9 thousand Fitbit downloads to iPhones and about 72 thousand downloads to Androids in the UK.
  • Wear OS by Google was released as Android Wear, but rebranded in 2018 to highlight the software’s ability to pair with different phones. Its creators pursued the goal of elaborating a truly optimized smartwatch compatible with Android and iOS. The operating system is used in various devices, including those developed by such companies as Fossil, Mobvoi, and Skagen. By 2022, Wear OS and Android are forecasted to run 37 million smartwatches globally, outpacing Apple’s watchOS, which is expected to be installed on 34.5 million watches. Wear OS products are compatible with phones running Android 6.0+ (except Go edition) or iOS 10.0+. Since the Android Wear 2.0 version, the system has been supporting standalone apps, entirely autonomous wearable applications, which can be installed from their native Google Play Market directly on the watch. Wear OS is almost an independent system that still operates within the framework of the Google Services infrastructure, complementing, but not relying on it.

How Do You Connect a Smartwatch to a Phone?

Apple Watch and iPhone don’t need extra tools to be paired, having a built-in synchronization utility embedded in their OS. To sync the two devices, a user should activate Wi-Fi and Bluetooth on both of them and follow the instructions displayed on the phone or turn to the official website for details. However, setting up most smartwatches with mobile phones requires additional utilities. For example, to connect Android Wear OS watches with any mobile device, the Wear OS application is needed. The same holds for Samsung’s smartwatches using the Galaxy Wearable app, and Fitbit having its app to pair with mobiles.

One should bear in mind that the smartwatch can be synced with one phone only, which means that to pair it with a new device, they should disconnect it with the previous one first. Nevertheless, several watches can be simultaneously synchronized with one mobile, but for iPhone.


A smartwatch has become a go-to for many people, comprising a myriad of functions, earlier available on separate devices only. It’s a handy multi-purpose solution, helping its users better manage their lives in plenty of ways: starting with ensuring their safety and ending with providing for e-transactions. At the moment, there are numerous options for all tastes, both standalone and those serving as a phone extension.

One of the most promising smartwatch operating systems is Wear OS that is expected to lead the market in two years. In the next article in the series, we will focus on the Wear OS app development, sharing our rich experience of how to create an upscale solution, sure to meet smartwatch users’ highest expectations. It will represent a practical guide for a Wear OS developer and outline all the necessary steps to follow, so stay tuned.

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