gulpfile.js

// jshint node:true, latedef:nofunc
'use strict';

var flo = require('fb-flo'),
    gulp = require('gulp'),
    path = require('path'),
    map = require('map-stream'),
    minimatch = require('minimatch'),
    lazypipe = require('lazypipe'),
    rimraf = require('rimraf'),
    PassThrough = require('stream').PassThrough,
    $ = require('gulp-load-plugins')(),
    lazy = {},
    server,
    reloader,
    globs;

require('longjohn');

globs = {
  less: 'less/**/*.less',
  js: 'js/**/*.js',
  extras: '*.*'
};

lazy.less = lazypipe()
  .pipe($.less)
  .pipe($.csso)
  .pipe(gulp.dest, 'dest/css')
  .pipe(reload)
  .pipe(exclude);

lazy.js = lazypipe()
  .pipe($.uglify)
  .pipe(gulp.dest, 'dest/js')
  .pipe(reload)
  .pipe(exclude);

gulp.task('flo', function(done) {
  server = flo('app', {
    port: 8888,
    host: 'localhost',
    verbose: 1,
    glob: ['**/*', '!**/*.tmp']
  }, resolver)
  .once('ready', done);
});

gulp.task('less', function() {
  return gulp.src(path.join('app', globs.less))
    .pipe(lazy.less());
});

gulp.task('js', function() {
  return gulp.src(path.join('app', globs.js))
    .pipe(lazy.js());
});

gulp.task('extras', function () {
  return gulp.src(path.join('app', globs.extras), { dot: true })
    .pipe(gulp.dest('dest'));
});

gulp.task('clean', function(done) {
  rimraf('dest', done);
});

gulp.task('build', ['less', 'js', 'extras']);
gulp.task('rebuild', ['clean'], function() {
  gulp.start('build');
});

function resolver(filepath, callback) {
  reloader = map(function(file, cb) {
    callback({
      reload: !!reload,
      resourceURL: path.relative('dest', file.path).replace('\\', '/'),
      contents: file.contents.toString()
    });
    cb(null, file);
  });

  gulp
    .src(path.resolve('app', filepath))
    .pipe($.if(minimatch(filepath, globs.less), lazy.less()))
    .pipe($.if(minimatch(filepath, globs.js), lazy.js()))
    .pipe(gulp.dest('dest'))
    .pipe(reload(1));
}

function exclude() {
  return map(function(file, callback) {
    callback();
  });
}

function reload() {
  if (typeof reloader !== 'undefined') return reloader;

  return new PassThrough({ objectMode: true });
}

Nice update with the build step. Maybe you could also add a default step (that builds and starts flo)?

Maybe it would be nice to integrate a server (maybe with livereloading for html) to serve the files?