diff --git a/comms.js b/comms.js
index 78841bc6e..9442187a5 100644
--- a/comms.js
+++ b/comms.js
@@ -18,18 +18,39 @@ uploadApp : app => {
   return new Promise((resolve,reject) => {
     // Load all files
     Promise.all(app.storage.map(storageFile => {
-      var promise;
       if (storageFile.content)
-        promise = Promise.resolve(storageFile.content);
+        return Promise.resolve(storageFile);
       else if (storageFile.url)
-        promise = httpGet("apps/"+storageFile.url);
-      else promise = Promise.resolve();
+        return httpGet("apps/"+storageFile.url).then(content => {
+          return {
+            name : storageFile.name,
+            content : content,
+            evaluate : storageFile.evaluate
+        }});
+      else return Promise.resolve();
+    })).then(fileContents => { // now we just have a list of files + contents...
+      // filter out empty files
+      fileContents = fileContents.filter(x=>x!==undefined);
       // then map each file to a command to load into storage
-      return promise.then(contents =>
-        contents?`\x10require('Storage').write(${toJS(storageFile.name)},${storageFile.evaluate ? contents.trim() : toJS(contents)});`:"")
-    })) // now we just have a list of commands...
-    .then((fileContents) => {
-      fileContents = fileContents.join("\n")+"\n";
+      fileContents.forEach(storageFile => {
+        // check if this is the JSON file
+        if (storageFile.name[0]=="+") {
+          storageFile.evaluate = true;
+          var json = {};
+          try {
+            json = JSON.parse(storageFile.content);
+          } catch (e) {
+            reject(storageFile.name+" is not valid JSON");
+          }
+          json.files = fileContents.map(storageFile=>storageFile.name).join(",");
+          storageFile.content = JSON.stringify(json);
+        }
+        // format ready for Espruino
+        var js = storageFile.evaluate ? storageFile.content.trim() : toJS(storageFile.content);
+        storageFile.cmd = `\x10require('Storage').write(${toJS(storageFile.name)},${js});`;
+      });
+
+      fileContents = fileContents.map(storageFile=>storageFile.cmd).join("\n")+"\n";
       console.log("uploadApp",fileContents);
       // reset to ensure we have enough memory to upload what we need to
       Puck.write("\x03reset();\n", (result) => {