If you want a smartwatch, but you own an Apple (NASDAQ:AAPL) iPhone, you pretty much have only one choice: the Apple Watch. However, your choices just got a bit broader as Google (NASDAQ:GOOG) (NASDAQ:GOOGL) has introduced a new app, Android Wear for iOS, which enables Android Wear watches to work with the iPhone.

The new app is only compatible with a couple of different models currently, with two more soon to be released. Still, the move gives iPhone owners several options, including a few priced well below the Apple Watch's $349 entry point. Will the new compatibility spur sales of Android Wear watches?

Androidwearforios
The new Android Wear for iOS app sends notifications to Android Wear devices. Source: Google.

What you can and cannot do with an Android Wear watch and an iPhone
The new Android Wear for iOS app enables a surprisingly robust feature set for Android Wear devices. All of your iOS notifications -- or just the ones you want -- are mirrored on the device, Google Now cards work, and you can reply to emails through Gmail, and set appointments through Google Calendar. You can get all the basic functionality of an Android Wear watch.

But you don't have access to third-party apps due to Apple's restrictions on competing app stores. While there are only a few dozen interesting third-party smartwatch apps at this point, it's still a glaring omission. The app ecosystem is still very young and could become much more significant during the next two years.

Additionally, as you might expect, Android Wear devices aren't compatible with Apple services like HealthKit. And while it can stream and control music,  it can't search for songs on Apple Music like Siri can.

All told, it doesn't work as well as an Apple Watch does, nor does it work as well as an Android Wear device works with an Android Phone. Still, for iPhone owners looking for an inexpensive way to test a smartwatch, it will provide a good sense of what it's like.

But how much of a boost could we expect?
Apple owners are particularly loyal to the Apple brand, so even given the option, it's likely the vast majority will opt for an Apple Watch over an Android Wear device. Even so, Apple commands less than 20% of the global smartphone market, so even a relatively strong percentage of iPhone users opting for an Android Wear device wouldn't result in a huge increase in sales.

But sales for Android Wear devices have been lacking. Last quarter, Apple sold 3.6 million Apple Watches, according to IDC, and that's in just more than two months of sales. While there are no exact numbers on the total number of Android Wear devices sold, Samsung wasthe highest-selling Android Wear manufacturer on the list.

The Korean company sold 600 million smartwatches last quarter, but not all of them run Android Wear. The Samsung Gear 2, Gear 2 Neo, and Gear S all run Tizen -- an alternative to Android -- and the upcoming Gear S2 will run Tizen, as well.

A modest boost in Android Wear sales from iPhone owners could provide a significant increase in sales percentage-wise. Still, it's not going to make Google's smartwatches much more competitive with the Apple Watch.

A nascent market
Even though smartwatches have been around for a couple of years in their current form, it's still a nascent market. Many consumers are taking a wait-and-see approach to see how it all shakes out. Apple certainly gave a kick-start to the market, accounting for about 20% of all wearable devices last quarter, including less-expensive fitness trackers.

It may still be a couple more years before smartwatches really start to catch on, and it's unlikely Apple will make the Apple Watch compatible with Android. So Google shouldn't be trying to court the small percentage of iPhone owners interested in something different; it needs to court the huge number of Android owners who aren't yet sold on a smartwatch.

Adam Levy owns shares of Apple. The Motley Fool owns and recommends Apple, Google (A shares), and Google (C shares). Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.