Google (GOOG 0.72%) (GOOGL 0.83%) has finally launched an iOS version of its Android Wear mobile app, which could undermine the dominance of Apple (AAPL 1.66%) Watch on iOS devices. Android Wear for iOS only officially supports newer Android Wear watches like the LG Watch Urbane and Huawei Watch, but older devices that have been updated to Android Wear 1.3 can also connect to iPhones.

Huawei Watch (L) and LG's Watch Urbane (R). Source: Company websites.

When paired with iPhones, Android Wear devices display notifications from Google, Apple, and third-party iPhone apps. However, iOS users won't be able to install any third-party Android Wear apps from Google Play. This leaves Android Wear developers out in the cold, but Google claims that it will eventually bring third-party app support to iOS users. The devices also still lack Wi-Fi support.

Why Google is connecting Android Wear to iOS
Despite those shortcomings, launching Android Wear to iOS can help Google expand its ecosystem. This move complements the launches of Chrome, Google Now, Drive, YouTube, Google Maps, and other apps for iOS -- all of which tether iOS users to Google services.

However, Google and Apple's ecosystems now overlap in many areas. Safari, Siri, Apple Maps, and iCloud all face the disruptive growth of Google's iOS apps. That's why Apple replaced Google with Bing as the default search engine for Siri and Spotlight Search, and might do the same for Safari soon. Apple is also letting developers create ad blocking extensions for Safari in iOS 9 -- a move that could impact 75% of Google's mobile ad revenues. Apple also locks Google Maps out of its dashboard mirroring platform CarPlay, which forces users to rely on Apple Maps instead.

Apple previously tried to block competing apps altogether, but it has relaxed that policy over the past few years. However, it can still wage a more subtle war against Google by quietly locking it out of certain parts of its ecosystem.

Why this move won't hurt Apple
The launch of Android Wear for iOS gives iPhone users a wider selection of smartwatches to choose from, but sales figures indicate that the Apple Watch will be a tough device to beat.

Research firm IDC recently stated that Apple had shipped 3.6 million Apple Watches over the past four months, making it the top smartwatch maker in the world. Samsung, the market leader last year, only shipped 600,000 wearable devices during the quarter. Strategy Analytics says the Apple Watch claimed 75.5% of the entire smartwatch market during its launch quarter, compared to Samsung's 7.5% share.

Apple Watch. Source: Apple.

Research firm Smartwatch Group estimates that 89 companies sold a total of 6.8 million smartwatches worldwide last year. Many of those devices ran proprietary operating systems instead of Android Wear. That prompted many industry watchers to claim that Android Wear had "failed," and that the industry needed the Apple Watch to turn the niche smartwatch market into a mainstream one.

It's surprising that fewer Android Wear devices were sold than Apple Watches during the past quarter since Android has a much larger mobile market share. This indicates that letting iPhone owners buy Android Wear devices might barely impact Apple Watch sales.

But Apple might gain the upper hand
After the launch of the iPhone 6, CEO Tim Cook claimed that 85% of new iPhone buyers switched from other mobile platforms, mostly Android. To convert even more Android owners, Apple recently unveiled an iOS 9 app that will let Android users transfer their message history, saved photos and videos, accounts, wallpaper, DRM-free media, and other things over to iOS. The app can also automatically locate iOS versions of a user's favorite Android apps.

Letting Google launch Android Wear for iOS actually complements that strategy. Android users who bought Android Wear devices likely thought they would only be compatible with Android phones. But now that Android Wear devices are compatible with both platforms, Android owners have one less reason to keep using Android instead of iOS.

The key takeaway
The introduction of Android Wear for iOS and newer devices like the Huawei Watch might interest some iOS users, but they probably won't hurt Apple Watch sales. Android Wear devices didn't do great on Android, so it's silly to expect them to do much better on iOS. Instead, the effort could help lower the barriers between Android and iOS and cause more Android owners to buy iPhones instead.