Until now, Google Maps and Waze (also owned by Google) were the only navigation apps to be fully supported on Android Auto — others were restricted to the phone interface. This is now changing as popular alternative Sygic becomes one of the first third-party navigation apps to have native support for Android Auto.
Earlier this month, a beta build of Sygic for Android Auto was made available to registered testers and Redditor u/jesusbabio shared some images of it. The new UI is tailor-made for head units and is much better optimized than the phone interface that was previously available.
As seen in the images, the application seems to offer a simplistic interface that offers necessary information without distracting the driver with a cluttered panel.
The Android Auto build for Sygic is still in beta and it's not known when the app will be made available to all users. However, if you want to check it out, sign up for Sygic betas via the Google Play Store listing and ensure you've updated to version 19 (which you can grab from APK Mirror). Once installed, you'll need to activate the Android Auto trial license from the Sygic Store to get started.
If you're wondering why a third-party navigation app on Android Auto is noteworthy, you need to know that Google Maps and Waze aren't perfect offerings. Even though they satisfy the needs of millions of people around the world, they don't serve all driving needs. For instance, Sygic is the preferred choice of navigation app for some users because it offers an offline navigation solution, which is more convenient and lightweight than, say, the solution Google Maps has to offer.
It was only earlier this year that Google announced it would enable support for third-party apps in Android Auto categories of navigation, parking, and electric vehicle charging. Sygic is one of the various early access partners that is working with Google to test the new APIs. Once they're made public, we can expect many more useful third-party Android Auto apps to be released.