After a summer of offering sponsored Wi-Fi in Manhattan, Google is extending its offer through September — but not for everyone. The company announced that it will be partnering with hotspot provider Boingo to promote Google Play, much as it did for Google Offers this summer. That means that in exchange for seeing some promotions for Play, users can get free Wi-Fi at 15 airports, a handful of New York subway stations, and "thousands" of hotels, malls, and other places nationwide. The offer will last until the end of September, and it's supposed to encompass a total of about 4,000 hotspots.

The airport and subway listings appear similar to before, but the total listings are greatly expanded from the initial promotion. Unlike the Google Offers deal, though, Google is pushing its own ecosystem for Play. Boingo has confirmed with us that while both Mac and PC computers can connect to the internet for free, only Android mobile devices will get the same treatment. When we went online with a laptop in a nearby subway station, it directed us to Google Play-sponsored internet. Connecting through the iPhone, however, gave us a separate "complimentary Wi-Fi" offer sponsored by Boingo, something that let us get online but likely isn't available in all locations.