Build an Auction site - Danish and English

The HomePage should be an auction site for retro objects (old and new produkts) for private people and companies with bidding, buy it now or make an proposal (like Ebay) It should have different categories for furnitueres, glas, ceramiqe and so on. Can you make a proposal for making a HomePage optimized for Iphone/IPad, Android and a sign in true Facebook and/or also give people the chance to sign in optional via Twitter, outlook, Instagram - as simple as possible to make as many people sign up easy. Please see to clarify what I think of: http://www.asp.net/mvc/tutorials/mvc-5/create-an-aspnet-mvc-5-app-with-facebook-and-google-oauth2-and-openid-sign-on Al pictures people take with therir smartphones should be stored automatacily at my companys Facebook profile to avoid my HomePage being slow and take to much space at my hoast - they should ofcauce be linked to the specific auction automatacly. I do not know if it’s nessesary to make and app to handle this easy ? There should be payment possibillities truewired bank transfer, PayPal, Swish and MobilePay (Danske Bank system) both are payments systems via Mobile Phones and developed off Scandinavian companies. The flashing layout at my homepage could be like the shops [login to view URL] make on Facebook. The page should have possibillities to STAR (5) the item when delivered and a text. I want things to be so easy to understand for people to avoid loosing customers and ofcause easy to reg. items and upload Pictures. You can maybe have a look at [login to view URL] (Swedish Company bougth of Ebay some years ago) the also have an app in appstore. I wan’t the service for the client to be as cheap as possible, maybe free - still thinking about it... Please feel free to ask questions - ofcause I have to hold Down my costs for this programming and I know it’s difficult to estimate hours but do your best :-)