Paytm an Indian company which was launched couple of years ago. When Indian government Ban 500 and 2000 rupees notes in currency. Then people started using Paytm and their paid through digital payments to shopkeepers another retail stores.
It was very helpful that time. You can easily pay money by putting mobile number. I personally use this app alot.
It is an Indian company. The customer service also very good on paytm.
I strongly recommend you to use this app for cashless transaction.