Google Maps for Android now supports Transit Navigation, with updated access to directions, better suggested search results and a photo viewer and Place pages. Google Maps Navigation (Beta) can help you whether you are traveling to an unfamiliar part of town or visiting a city across the world.
Google Maps Navigation (Beta) currently provides over 12 billion miles of GPS-guided driving and walking directions per year. Now, GPS turn-by-turn (or in this case, stop-by-stop) navigation is available for public transit directions in 400+ cities around the globe with Transit Navigation. This includes four metro cities in India – Bangalore (Bangalore Metropolitan Transport Corporation Ltd), Chennai (Chennai MRTS), Kolkata (Kolkata Metro) and Delhi (Delhi Metro Rail).
Transit Navigation uses GPS to determine your current location along your route and alerts you when it’s time to get off or make a transfer. This is particularly helpful if you’re in a city where you don’t speak the language and can’t read the route maps or understand the announcements. After starting your trip with Transit Navigation, you can open another application or put your phone away entirely and Google Maps will still display an alert in your notification bar and vibrate your phone when your stop is coming up. [source]