Boingo just announced that Google Play is now sponsoring free WiFi at 4,000 hotspots, including a number of major airports like New York’s JFK, Chicago’s O’Hare and Seattle-Tacoma, as well as Manhattan subway stations and “thousands of hotels, shopping malls, cafés and recreational areas.” This free service is scheduled to last through September, but it’s worth noting that Google and Boingo are explicitly noting that only Android phones and tablets, as well as Windows and Macintosh laptops will be able to make use of this service.

These WiFi hotspots are part of Boingo’s Cloud Nine Media platform, which offers advertisers the ability to “reach a captive audience through Wi-Fi sponsorships.” Boingo acquired Cloud Nine Media, which was founded by an ex-Google employee, in August.