diff --git a/app.js b/app.js
new file mode 100644
index 0000000..035e771
--- /dev/null
+++ b/app.js
@@ -0,0 +1,61 @@
+// Do not remove! This file needed for uses library offline.
+
+var fs = require('fs');
+var express = require('express');
+var requestJson = require('request-json');
+var objectAssign = require('object-assign');
+
+var app = express();
+
+app.use('/modules', express.static(__dirname + '/modules'));
+app.use('/binaries', express.static(__dirname + '/binaries'));
+
+app.get('/', function(req, res) {
+  res.send('Hello World!');
+});
+
+app.get('/json/boards.json', function(req, res) {
+  var client = requestJson.createClient('http://espruino.com/');
+  client.get('json/boards.json', function(err, _, originalJson) {
+    if (err) {
+      originalJson = {};
+    }
+
+    fs.readFile(__dirname + '/json/boards.json', function(err, data) {
+      var localJson = JSON.parse(data);
+      var resultJson = objectAssign(originalJson, localJson);
+      res.send(resultJson);
+    });
+  });
+});
+
+app.get('/json/*', function(req, res) {
+  var root = __dirname + '/json';
+  var filename = req.params[0];
+  fs.access(root + '/' + filename, fs.F_OK, function(err) {
+    if (err) {
+      res.redirect('http://espruino.com/json/' + filename);
+    } else {
+      res.sendFile(filename, { root: root });
+    }
+  });
+});
+
+// The 404 Route
+app.get('*', function(req, res) {
+  if (req.url.indexOf('amperka') > -1 || req.url.indexOf('@') > -1) {
+    console.log('Not found:', req.url);
+    res.status(404).send('Not found');
+  } else if (req.originalUrl.indexOf('/modules/') === 0) {
+    var module = req.originalUrl.substr('/modules/'.length);
+    console.log('Redirect for:', module);
+    res.redirect('http://espruino.com/modules/' + module);
+  }
+});
+
+var server = app.listen(3001, function() {
+  var host = server.address().address;
+  var port = server.address().port;
+
+  console.log('App listening at http://%s:%s', host, port);
+});