Mr Zuckerberg said the design focused on "rich stories, visual and engaging, your choice of different feeds...and a mobile inspired consistent UI (user interface)."
More top news
Two private citizens have already paid a "significant deposit" to take the week-long trip.
Slippy start tomorrow with frost & ice
The court will determine how much the UK government and travel firms knew about the risk of an attack on tourists holidaying in the area.