Messaging service Viber today rolled out a new Secret Chats feature. Not to be confused with Secret Messages, a similar feature introduced in February 2017 that lets you define how long your photos, videos and texts are available after the recipient has opened them, Secret Chats use Vibers end-to-end encryption let you set a timer on individual messages so they disappear after a few seconds, get an alert when a screenshot is taken and be sure no messages get forwarded.
As I understand you are well informed. I have a such question: if it be necessary, can my private correspondence, photos, videos get to third persons?