Whatsapp Shopping ECommerce Android App Development

25% Payment will be released after completion of 50% work and showing us working Apk. We will not even award you or create milestone the project without checking your 50% work. I need an Android app where people could shop grocery and vegetables using whatsapp. Similarly people are shopping on Meesho app. Once users add items in the cart and pay the bill or select COD, app should give a message . Congrats Your order is placed successfully and will be delivered within 60 minutes and one countdown timer should begin 60-59-58-57 like this. An invoice should be sent to buyer's mail and on whatsapp also in Pdf format. Sms Api to be integrated for Otp authentication as well as successful transaction. In cart all the bills to be calculated according to GST in that category. It should be very easy to use by customers. They should be able to make payment using whatsapp only and by other payment gateway also. There should be customer dashboard and admin dashboard. Source code of the app shoukd be handed over to us after completion of app in perfectly working condition. App should work on all Android versions above 4.0 snd it should not crash. If it is crashing then we will ask you unlimited times to solve it and you will have to solve it.