How secure are Snapchat-style apps?

Ephemeral messaging apps such as Snapchat, Wickr and Frankly, all of which advertise that your photo, message or update will only be accessible for a short period, are on the rise. Snapchat and Frankly, for example, claim they permanently delete messages, photos and videos after 10 seconds. After that, there’s no record.

Source: CNN Top Stories