Appremix has released an update to its Boxcar Push Notification application for the iPhone platform. Boxcar 3.0 is now a universal app, adding iPad support and a revamped inbox with a pull-down-to-refresh feature, the ability to delete individual notifications and five new notification sounds. Notably, all push notification services offered by Boxcar are now freeāprevious versions provided one service at no charge and required users to purchaseā¦