Getting error in a socket.io chat client on heroku

i have uploaded a node.js , express chat app to heroku but it does not work log-

2017-03-12T15:55:42.109224+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=socializechat.herokuapp.com request_id=d9a5ae24-a977-4c7e-83ff-e0e1dc989936 fwd="47.15.1.56" dyno= connect= service= status=503 bytes= protocol=https Please help

via ironman