Android Wear is one of the most popular operating systems for wearables with a number of smartwatches that use the OS from the likes of ASUS, Moto, and Huawei. In order to control an Android Wear smartwatch, pair it with a smartphone and change a number of settings or preferences, users are required to download the Android Wear app onto their smartphones.
Until yesterday, the app was listed under "1,000,000 - 5,000,000" downloads on the Play Store, which hints at the number of users, but wasn't necessarily precise considering the fact that the app hit this milestone way back in March 2015. Today, though, the app now finds itself under the "5,000,000 - 10,000,000" downloads category, meaning the app has just hit 5 million downloads. Now, although Google doesn't release the number of active users for its wearable system, the number of downloads does provide a strong guide of where this number may hover at. Considering that a number of these downloads may come from people simply re-installing the app after switching smartphones, it's impossible to come up with an exact number of users, but what it does indicate is that the number of active users is now closer to the 5 million mark.
One of the reasons Google doesn't reveal the number of users is simple. Tracking Android Wear device activations are much harder than tracking smartphones due to the fact that they aren't connected to Google Play Services and, most of the time, are extensions of smartphones. Although it is harder to track, though, that doesn't mean it's impossible and Google is sure to have a rough number of active devices. Google is still actively investing in the platform and only back in May did we see a complete overhaul of the system revealed, which brought a number of big improvements and new features, such as a new design and standalone apps. Aside from the company's active investments, the wearable market is also still in the process of growing, so Android Wear is sure to grow with it and, with a number of Android Wear watches in the works, as well as the rumored pair of Nexus smartwatches, Google is likely to reveal user numbers once it feels they are impressive enough.