I have purchased many products from Flipkart. And I can say it is one of the Best online shopping website.
The most important is Customer Service it gives You all the info from product order to delivery and shipping.
All the product that I have purchased so far are 100% Genuine and top notch.
Products that I have returned had fit issue but never quality issue sometimes its the quality that is not good but many times is good.
delivery is also quick usually 3-4 days even in late cases it takes not more than 5 days to deliver.App and websites work good But Apps lags sometimes in slow connections but overall Good.
In the end I just want to say that its a great site to shop from reliable and quickly deliver Products.