From the post: "One important change you should know about is that Latitude and check-ins will be retired. These features will no longer be a part of the new G

From the post: "One important change you should know about is that Latitude and check-ins will be retired. These features will no longer be a part of the new Google Maps app, and will stop functioning in older versions by August 9. We understand some of you still want to see your friends and family on a map, which is why we've added location sharing and check-ins to Google+ for Android (coming soon to iOS)"