gulpfile.js

var gulp = require('gulp');
var nodemon = require('gulp-nodemon');
var browserSync = require('browser-sync').create();

gulp.task('gulp_nodemon', function () {
nodemon({
script: './server/server.js'           //this is where my express server is
, ext: 'js html css'          //nodemon watches *.js, *.html and *.css files
, env: { 'NODE_ENV': 'development' }
});
});

gulp.task('sync', function(){
browserSync.init({
port: 3002,                      //this can be any port, it will show our app
proxy: 'http://localhost:3000/', //this is the port where express server works
ui: {port: 3003},                //UI, can be any port
reloadDelay: 100                //Important, otherwise syncing will not work
});
gulp.watch(['./**/*.js', './**/*.html', './**/*.css']).on("change",
browserSync.reload);
});

gulp.task('default', ['gulp_nodemon', 'sync']);