Google is now allowing app developers access to their APIs for Android Auto, which the company said will allow for Android apps made for smartphones and tablets to "be extended to the car in a way that is optimized for the driving experience."

Google said:

For users, this means they simply connect their Android handheld to a compatible vehicle and begin utilizing a car-optimized Android experience that works with the car's head unit display, steering wheel buttons, and more. For developers, the APIs and UX guidelines make it easy to provide a simple way for users to get the information they need while on the road. As an added bonus, the Android Auto APIs let developers easily extend their existing apps targeting Android 5.0 (API level 21) or higher to work in the car without having to worry about vehicle-specific hardware differences. This gives developers wide reach across manufacturers, model and regions, by just developing with one set of APIs and UX standards.

At first, only audio and messaging Android apps can be supported by Android Auto but Google says that more app categories will be added in the future. Some of the first Android Auto apps will be from iHeartRadio, Joyride, Kik,, NPR, Pandora, PocketCasts, Songza, SoundCloud, Spotify, Stitcher, TextMe, textPlus, TuneIn, Umano, and WhatsApp. Audi and Volvo have confirmed they will have cars that support Android Auto.

Source: Google