LokLok is one of the coolest chat programs I have heard about recently. LokLok works directly on your lock screen to chat with friends and family. LokLok takes your lock screen and creates a shared lock screen that only your inner circle can see. The lock screen is sync with others in you group. You can take a picture and then scribble a message which someone close to you can see and respond to. The groups are private and no history is saved.
Check out LokLok HERE