Passengers on India's vast railway network have long complained of the terrible meals offered to sustain them on long journeys, but a slew of new services that bring fast food to their seats is changing the way they dine.

From Kentucky Fried Chicken to Domino's pizza and a host of local delicacies, train passengers now have access to a vast array of hot dishes - all at the click of a smartphone app.

For passenger Amit V, who ordered a vegetarian curry dish to be delivered to his seat, the new services are a godsend after years of buying railway food that he said was often inedible.