Apple has posted details of its iPhone 4 case program. According to the webpage, iPhone 4 users who want to receive a free case need to download the free iPhone 4 Case Program app from the App Store. Once the app is installed, users need to login with their iTunes Store account or Apple ID. The app checks the device’s IMEI and serial number to verify that the user indeed does own an iPhone 4, and lets the user choose an iPhone 4 Bumper or another case. Apple notes that for iPhone 4 purchases made before July 23, 2010, users must apply no later than August 22, 2010; otherwise, they must apply within 30 days of the iPhone 4 purchase. For advice on picking your free case, take a glance at our recommendation article.