It is an app where you can transfer money from one bank account to another bank account. It is application where you can do recharge, book tickets etc. They even give money for inviting your friends to this application when the your friend does the first transaction successfully. There are similar application available in the market. In this application when you refer your friends money is added in your phonepe wallet which cannot besend to the bank account directly where as in Google Pay(Tez) you receivemoney directly in your bank account which is good thing about Google Pay.
Basically you can’t use your money wherever you want. Like most of the stores have paytm option where you can pay using paytm, But money in phonepe wallet cannot be used at stores as well, because they don’t many stores which accept money from phonepe. This is the major drawback of this application.