Application error message when trying to open heroku app - node.js

Question

I'm new to nodejs and trying to deploy a simple word game to heroku. i followed the instruction on heroku website and everyting works until the last command "heroku open" and it opens a web browser with the following message:
"An error occurred in the application and your page could not be served. Please try again in a few moments.
If you are the application owner, check your logs for details."
The heroku logs shows:
2016-08-04T18:56:36.552635+00:00 heroku[api]: Enable Logplex by teamsky916#gmail .com
2016-08-04T18:56:36.552635+00:00 heroku[api]: Release v2 created by teamsky916#g mail.com
2016-08-04T18:58:34.328360+00:00 heroku[router]: at=info code=H81 desc="Blank ap p" method=GET path="/" host=build-word-game.herokuapp.com request_id=f238942c-ef aa-4011-b505-7e5f062221a3 fwd="107.77.75.83" dyno= connect= service= status=502 bytes=
2016-08-04T18:58:35.171645+00:00 heroku[router]: at=info code=H81 desc="Blank ap p" method=GET path="/favicon.ico" host=build-word-game.herokuapp.com request_id= a02c27ef-865c-48e3-91cd-bd6e29ca51e3 fwd="107.77.75.83" dyno= connect= service= status=502 bytes=
2016-08-04T19:26:43.069903+00:00 heroku[api]: Scale to web=1 by teamsky916#gmail .com
2016-08-04T19:26:43.070467+00:00 heroku[api]: Deploy 4725c48 by teamsky916#gmail .com
2016-08-04T19:26:43.070552+00:00 heroku[api]: Release v3 created by teamsky916#g mail.com
2016-08-04T19:26:43.473784+00:00 heroku[slug-compiler]: Slug compilation finishe d
2016-08-04T19:26:43.473765+00:00 heroku[slug-compiler]: Slug compilation started
2016-08-04T19:26:45.915539+00:00 heroku[web.1]: Starting process with command `n ode server.js`
2016-08-04T19:26:50.481084+00:00 app[web.1]: listening to port 3000!
2016-08-04T19:27:46.488886+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2016-08-04T19:27:46.488886+00:00 heroku[web.1]: Stopping process with SIGKILL
2016-08-04T19:27:46.631684+00:00 heroku[web.1]: Process exited with status 137
2016-08-04T19:27:46.618404+00:00 heroku[web.1]: State changed from starting to c rashed
2016-08-04T19:27:46.619564+00:00 heroku[web.1]: State changed from crashed to st arting
2016-08-04T19:27:48.599634+00:00 heroku[web.1]: Starting process with command `n ode server.js`
2016-08-04T19:27:51.304417+00:00 app[web.1]: listening to port 3000!
2016-08-04T19:28:48.755864+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2016-08-04T19:28:48.755938+00:00 heroku[web.1]: Stopping process with SIGKILL
2016-08-04T19:28:48.879934+00:00 heroku[web.1]: Process exited with status 137
2016-08-04T19:28:48.893371+00:00 heroku[web.1]: State changed from starting to c rashed
2016-08-04T19:31:31.210359+00:00 heroku[router]: at=error code=H10 desc="App cra shed" method=GET path="/" host=build-word-game.herokuapp.com request_id=e0536d30 -8590-453d-9a04-fb8a56eb6893 fwd="107.77.213.153" dyno= connect= service= status =503 bytes=
2016-08-04T19:31:32.552715+00:00 heroku[router]: at=error code=H10 desc="App cra shed" method=GET path="/favicon.ico" host=build-word-game.herokuapp.com request_ id=89bfb417-9793-4687-b400-72cc34d16ea8 fwd="107.77.213.153" dyno= connect= serv ice= status=503 bytes=
2016-08-04T19:53:16.445270+00:00 heroku[web.1]: State changed from crashed to st arting
2016-08-04T19:53:18.025971+00:00 heroku[web.1]: Starting process with command `n ode server.js`
2016-08-04T19:53:19.981109+00:00 app[web.1]: listening to port 3000!
2016-08-04T19:54:18.509309+00:00 heroku[web.1]: Stopping process with SIGKILL
2016-08-04T19:54:18.509204+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2016-08-04T19:54:18.601875+00:00 heroku[web.1]: Process exited with status 137
2016-08-04T19:54:18.606261+00:00 heroku[web.1]: State changed from starting to c rashed
2016-08-04T19:59:58.452903+00:00 heroku[router]: at=error code=H10 desc="App cra shed" method=GET path="/" host=build-word-game.herokuapp.com request_id=450b80d9 -a366-4e0f-9426-ff89eac931fb fwd="107.77.213.153" dyno= connect= service= status =503 bytes=
2016-08-04T19:59:59.109794+00:00 heroku[router]: at=error code=H10 desc="App cra shed" method=GET path="/favicon.ico" host=build-word-game.herokuapp.com request_ id=1eecc47a-5334-4a38-bd8d-093a9164ead5 fwd="107.77.213.153" dyno= connect= serv ice= status=503 bytes=
2016-08-04T20:01:28.744667+00:00 heroku[router]: at=error code=H10 desc="App cra shed" method=GET path="/" host=build-word-game.herokuapp.com request_id=a2d52aea -d7fc-4f18-b023-50aa8e93587c fwd="107.77.213.153" dyno= connect= service= status =503 bytes=
2016-08-04T20:01:29.378063+00:00 heroku[router]: at=error code=H10 desc="App cra shed" method=GET path="/favicon.ico" host=build-word-game.herokuapp.com request_ id=8e62ab9c-50a3-43eb-9579-9c3d4a6c9d42 fwd="107.77.213.153" dyno= connect= serv ice= status=503 bytes=
I appreciate your help.

Answer 1

It looks like your Node application is not starting properly. This is likely due to you not binding your Node server to the correct port.
On Heroku, you must bind your Node server to a port number specified in the PORT environment variable. This is because Heroku magically handles routing for your requests, on a server with many other applications.
What you should do is modify your Node code so that it listens on port process.env.PORT.
Here's an example Express.js application that listens to the correct port, as an example:
var express = require('express');
var app = express();
app.listen(process.env.PORT);