Deletion of single messages
Click two seconds on a message or an attachment and select “delete” in the appearing menu.
Deletion of a conversation
iOS: A whole conversation can be deleted when opening the corresponding chat and clicking on the action button on the upper right. Chose “delete all xxx messages” to delete the whole conversation. Files previously saved to the device’s storage remain unaffected.
Android: Delete a conversation by clicking two seconds on the chat to be deleted (in tab “Chats”) and confirm action by clicking “delete”.