I believe they are available only at London Westfield and Bluewater shopping centers. So it should be from iPilot which has got really good reviews.
"This 15 minute experience includes a short flight and one landing at an airport of your choice each. There are over 500 airports for you to choose from, and favourites include London Heathrow, St. Maarten and Hong Kong’s Kai Tak Airport."
15min experience are priced at £49 which works out little over £40 for 2 people with the 20% off voucher code.
30min experience are priced at £99 which works out little over £80 for 2 people with the 20% off voucher vode.
I've used the voucher code "123123" but they are more in the vouchers section like "NATWEST"
12% Quidco/TCB is available but most likely get declined if a voucher code is used.