It sounds like something out of a spy movie: A new app called Silent Circle allows users to "burn" sensitive messages sent on their phones.

Jon Callas, one of the people who developed the app, says the idea is pretty simple.

"It's a timer. So you can say, one hour; seven minutes. Whatever," Callas tells Jacki Lyden, host of weekends on All Things Considered.

It's called a "burn notice." When the time's up, the text is erased from both the sender and receiver's phones.

Callas and his business partners got the idea after hearing an all-too-familiar story: A friend of theirs inadvertently read a text meant for someone else.