Apple has changed its policies on the purchase of the Applecare+ warranty for it's iPhones to make it a bit easier to obtain. Previously you had to purchase it at the time the iPhone was purchased. But now you can purchase it up to 30 days from the date the iPhone was purchased. While there are some hoops to jump through, such as taking the iPhone into an Apple Store for inspection to verify it has not already been damaged, it is well worth the purchase.
You can see more details on the iPhone Applecare+ directly from Apple.