You may have experienced yourself getting locked out of the apartment. This is not unusual when you don't have a proper key holder that is always hanging with you. Designer Alex Reed designed an iPhone case which has a space to keep a key inside. Simply attach the key to the case and hide it inside. When you need the key, press the sliding button to get the key out and when you finished, press it backward to hide. Simple but useful to those who really in need. Seeks funding at kickstarter.