at=error code=H10 desc="App crashed" method=GET path="/" host=shopify-shipping-settings.herokuapp.com request_id=23480184-ae21-4b9b-a52f-e79e25dbee5f fwd="49.34.167.237" dyno= connect= service= status=503 bytes= protocol=https code example

Example: at=error code=h10 desc="app crashed" method=get path="/" host

Found solution for me here: Heroku + node.js error (Web process failed to bind to $PORT within 60 seconds of launch)

In my case my app crashed because I was hard setting the PORT, instead of using the port that heroku dinamicaly sets, which can be accessed with process.env.PORT

app.listen(process.env.PORT || 3000, function(){
  console.log("Express server listening on port %d in %s mode", this.address().port, app.settings.env);
});