I need app where i will add a product for which people will but this at nominal price to enter into say sweepstake eg iphone x in 10 rs.. people will buy this one for Rs. 10 then after completing certin no of entries the deal will be closed and the winner will be announsed on random choice. and same will be declared on site. This is the basic concept. the payment options will also be integrated for such. So provide me detailed project orientation.