I am using this app on and off for past 4 years.
There are a few positive points and a few negative as well.
First the app is easy to use, has several offers, has good listings.
Downside of this app is that it has issues with customer service and has long delivery times as sometimes the delivery partner is often asked to deliver more than one order at a time. Also there is a huge price differential between actual hotel prices and the prices offered on zomato in case of some restaurants.