Nimki is the Gujrati name for Papri Chaat

Now papdi is a bit more difficult to define, because it can mean many things;

Papadi vegetable, a bean like shown here.

Or

Papri Chaat

Or a sweet called Sohan papdi or papri, a popular north Indian sweet made from besan flour; http://www.food-india.com/feature/products_review/P001_P050/images/P002_Haldirams_Soan_Papdi_Box.jpg