Google Maps was first made available for the Apple Watch in 2015, but was not available for download from 2017 onwards when Google dropped the app without explaining the reasons behind the decision.
However, Google Maps may be back on the Apple Watch, but it will not be as full of features as application of mobile. As 9to5Google notes, this new version does not allow you to search for a new location directly from Apple Watch. For spontaneous trips to places not stored on your watch, you need to use your phone to start the process, and then you can continue navigating the Apple Watch. So it's still a relatively basic experience, but it's nice to have for people who don't want to get stuck with Apple Maps.
To install the new app on Apple Watch, you must first update the Google Maps app on iPhone to the latest version 5.52. WatchOS requires watchOS 5 or later, which excludes the original Apple Watch.
Google's popular navigation returns to Apple Watch, but other apps have mysteriously abandoned mobile platform Apple, like official applications Twitter and Amazon, have not yet returned and we do not have any news about their possible return in the near future.
You can find Google Maps in the Apple App Store, and install it on your iPhone, here.