diff --git a/apps/gpsrec/interface.html b/apps/gpsrec/interface.html
index b87d75b3c..bc8dc48e1 100644
--- a/apps/gpsrec/interface.html
+++ b/apps/gpsrec/interface.html
@@ -5,32 +5,9 @@
   <body>
     <div id="tracks"></div>
 
-    <div class="modal active" id="status-modal">
-      <div class="modal-overlay"></div>
-      <div class="modal-container">
-        <div class="modal-header">
-          <div class="modal-title h5">Please wait</div>
-        </div>
-        <div class="modal-body">
-          <div class="content">
-            Loading...
-          </div>
-        </div>
-      </div>
-    </div>
-
     <script src="../../lib/interface.js"></script>
     <script>
 var domTracks = document.getElementById("tracks");
-var domModal = document.getElementById("status-modal");
-
-function showModal(title) {
-  domModal.querySelector(".content").innerHTML = title;
-  domModal.classList.add("active");
-}
-function hideModal(title) {
-  domModal.classList.remove("active");
-}
 
 function saveKML(track,title) {
   var kml = `<?xml version="1.0" encoding="UTF-8"?>
@@ -107,19 +84,15 @@ function trackLineToObject(l, hasTrackNumber) {
 }
 
 function downloadTrack(trackid, callback) {
-  showModal("Downloading Track...");
-  Puck.write(`\x10(function() {
-    var f = require("Storage").open(".gpsrc${trackid.toString(36)}","r");
-    var l = f.readLine();
-    while (l!==undefined) { Bluetooth.print(l); l = f.readLine(); }
-  })()\n`,tracklist=>{
-    hideModal();
-    var track = tracklist.trim().split("\n").map(l=>trackLineToObject(l,false));
+  Util.showModal("Downloading Track...");
+  Util.readStorageFile(`.gpsrc${trackid.toString(36)}`,data=>{
+    Util.hideModal();
+    var track = data.trim().split("\n").map(l=>trackLineToObject(l,false));
     callback(track);
   });
 }
 function getTrackList() {
-  showModal("Loading Tracks...");
+  Util.showModal("Loading Tracks...");
   domTracks.innerHTML = "";
   Puck.write(`\x10(function() {
     for (var n=0;n<36;n++) {
@@ -171,7 +144,7 @@ function getTrackList() {
     </div>
   </div>`;
     domTracks.innerHTML = html;
-    hideModal();
+    Util.hideModal();
     var buttons = domTracks.querySelectorAll("button");
     for (var i=0;i<buttons.length;i++) {
       buttons[i].addEventListener("click",event => {
@@ -179,9 +152,9 @@ function getTrackList() {
         var trackid = parseInt(button.getAttribute("trackid"));
         var task = button.getAttribute("task");
         if (task=="delete") {
-          showModal("Deleting Track...");
-          Puck.write(`\x10require("Storage").open(".gpsrc${trackid.toString(36)}","r").erase()\n`,()=>{
-            hideModal();
+          Util.showModal("Deleting Track...");
+          Util.eraseStorageFile(`.gpsrc${trackid.toString(36)}`,()=>{
+            Util.hideModal();
             getTrackList();
           });
         }
diff --git a/apps/heart/interface.html b/apps/heart/interface.html
index c2f115564..177e2cdfb 100644
--- a/apps/heart/interface.html
+++ b/apps/heart/interface.html
@@ -5,32 +5,9 @@
   <body>
     <div id="records"></div>
 
-    <div class="modal active" id="status-modal">
-      <div class="modal-overlay"></div>
-      <div class="modal-container">
-        <div class="modal-header">
-          <div class="modal-name h5">Please wait</div>
-        </div>
-        <div class="modal-body">
-          <div class="content">
-            Loading...
-          </div>
-        </div>
-      </div>
-    </div>
-
     <script src="../../lib/interface.js"></script>
     <script>
 var domRecords = document.getElementById("records");
-var domModal = document.getElementById("status-modal");
-
-function showModal(name) {
-  domModal.querySelector(".content").innerHTML = name;
-  domModal.classList.add("active");
-}
-function hideModal(name) {
-  domModal.classList.remove("active");
-}
 
 function saveRecord(record,name) {
   var csv = `${record.map(rec=>[rec.time, rec.bpm, rec.confidence].join(",")).join("\n")}`;
@@ -62,20 +39,16 @@ function recordLineToObject(l, hasRecordNbr) {
 }
 
 function downloadRecord(recordNbr, callback) {
-  showModal("Downloading heart rate record...");
-  Puck.write(`\x10(function() {
-    var f = require("Storage").open(".heart${recordNbr.toString(36)}","r");
-    var l = f.readLine();
-    while (l!==undefined) { Bluetooth.print(l); l = f.readLine(); }
-  })()\n`,recordList=>{
-    hideModal();
-    var record = recordList.trim().split("\n").map(l=>recordLineToObject(l,false));
+  Util.showModal("Downloading heart rate record...");
+  Util.readStorageFile(`.heart${recordNbr.toString(36)}`,data=>{
+    Util.hideModal();
+    var record = data.trim().split("\n").map(l=>recordLineToObject(l,false));
     callback(record);
   });
 }
 
 function getRecordList() {
-  showModal("Loading heart rate records...");
+  Util.showModal("Loading heart rate records...");
   domRecords.innerHTML = "";
   Puck.write(`\x10(function() {
     for (var n=0;n<36;n++) {
@@ -118,7 +91,7 @@ function getRecordList() {
     </div>
   </div>`;
     domRecords.innerHTML = html;
-    hideModal();
+    Util.hideModal();
     var buttons = domRecords.querySelectorAll("button");
     for (var i=0;i<buttons.length;i++) {
       buttons[i].addEventListener("click",event => {
@@ -126,9 +99,9 @@ function getRecordList() {
         var recordNbr = parseInt(button.getAttribute("recordNbr"));
         var task = button.getAttribute("task");
         if (task=="delete") {
-          showModal("Deleting record...");
-          Puck.write(`\x10require("Storage").open(".heart${recordNbr.toString(36)}","r").erase()\n`,()=>{
-            hideModal();
+          Util.showModal("Deleting record...");
+          Util.eraseStorageFile(`.heart${recordNbr.toString(36)}`,()=>{
+            Util.hideModal();
             getRecordList();
           });
         }
diff --git a/js/comms.js b/js/comms.js
index de2c328b3..05b94ffde 100644
--- a/js/comms.js
+++ b/js/comms.js
@@ -147,5 +147,50 @@ readFile : (file) => {
       });
     });
   });
+},
+readStorageFile : (filename) => { // StorageFiles are different to normal storage entries
+  return new Promise((resolve,reject) => {
+    // Use "\xFF" to signal end of file (can't occur in files anyway)
+    var fileContent = "";
+    var fileSize = undefined;
+    var connection = Puck.getConnection();
+    connection.received = "";
+    connection.cb = function(d) {
+      var finished = false;
+      var eofIndex = d.indexOf("\xFF");
+      if (eofIndex>=0) {
+        finished = true;
+        d = d.substr(0,eofIndex);
+      }
+      fileContent += d;
+      if (fileSize === undefined) {
+        var newLineIdx = fileContent.indexOf("\n");
+        if (newLineIdx>=0) {
+          fileSize = parseInt(fileContent.substr(0,newLineIdx));
+          console.log("File size is "+fileSize);
+          fileContent = fileContent.substr(newLineIdx+1);
+        }
+      } else {
+        showProgress(undefined,100*fileContent.length / (fileSize||1000000));
+      }
+      if (finished) {
+        hideProgress();
+        connection.received = "";
+        connection.cb = undefined;
+        resolve(fileContent);
+      }
+    };
+    console.log(`Reading StorageFile ${JSON.stringify(filename)}`);
+    connection.write(`\x03\x10(function() {
+      var f = require("Storage").open(${JSON.stringify(filename)},"r");
+      Bluetooth.println(f.getLength());
+      var l = f.readLine();
+      while (l!==undefined) { Bluetooth.print(l); l = f.readLine(); }
+      Bluetooth.print("\xFF");
+    })()\n`,() => {
+      showProgress(`Reading ${JSON.stringify(filename)}`,0);
+      console.log(`StorageFile read started...`);
+    });
+  });
 }
 };
diff --git a/js/index.js b/js/index.js
index d08d98cba..bfdabc22f 100644
--- a/js/index.js
+++ b/js/index.js
@@ -229,6 +229,14 @@ function handleAppInterface(app) {
               id : msg.id
             });
           });
+        } else if (msg.type=="readstoragefile") {
+          Comms.readStorageFile(msg.data/*filename*/).then(function(result) {
+            iwin.postMessage({
+              type : "readstoragefilersp",
+              data : result,
+              id : msg.id
+            });
+          });
         }
       }, false);
       iwin.postMessage({type:"init"});
diff --git a/lib/interface.js b/lib/interface.js
index 6156759b4..414c9d7fb 100644
--- a/lib/interface.js
+++ b/lib/interface.js
@@ -3,10 +3,21 @@ be used from within BangleApps
 
 See: README.md / `apps.json`: `interface` element
 
-This exposes a 'Puck' object like the puck.js library,
-and calls `onInit` when it's ready. `Puck` can be used
-for sending/receiving data to the correctly connected
+This exposes a 'Puck' object (a simple version of
+https://github.com/espruino/EspruinoWebTools/blob/master/puck.js)
+and calls `onInit` when it's ready. `Puck` can be used for
+sending/receiving data to the correctly connected
 device with Puck.eval/write.
+
+Puck.write(data,callback)
+Puck.eval(data,callback)
+
+There is also:
+
+Util.readStorageFile(filename,callback)
+Util.eraseStorageFile(filename,callback)
+Util.showModal(title)
+Util.hideModal()
 */
 var __id = 0, __idlookup = [];
 var Puck = {
@@ -20,11 +31,48 @@ var Puck = {
     window.postMessage({type:"write",data:data,id:__id});
   }
 };
+
+var Util = {
+  readStorageFile : function(filename,callback) {
+    __id++;
+    __idlookup[__id] = callback;
+    window.postMessage({type:"readstoragefile",data:filename,id:__id});
+  },
+  eraseStorageFile : function(filename,callback) {
+    Puck.write(`\x10require("Storage").open(${JSON.stringify(filename)}","r").erase()\n`,callback);
+  },
+  showModal : function(title) {
+    if (!Util.domModal) {
+      Util.domModal = document.createElement('div');
+      Util.domModal.id = "status-modal";
+      Util.domModal.classList.add("modal");
+      Util.domModal.classList.add("active");
+      Util.domModal.innerHTML = `<div class="modal-overlay"></div>
+      <div class="modal-container">
+        <div class="modal-header">
+          <div class="modal-title h5">Please wait</div>
+        </div>
+        <div class="modal-body">
+          <div class="content">
+            Loading...
+          </div>
+        </div>
+      </div>`;
+      document.body.appendChild(Util.domModal);
+    }
+    Util.domModal.querySelector(".content").innerHTML = title;
+    Util.domModal.classList.add("active");
+  },
+  hideModal : function() {
+    if (!Util.domModal) return;
+    Util.domModal.classList.remove("active");
+  }
+};
 window.addEventListener("message", function(event) {
   var msg = event.data;
   if (msg.type=="init") {
     onInit();
-  } else if (msg.type=="evalrsp" || msg.type=="writersp") {
+  } else if (msg.type=="evalrsp" || msg.type=="writersp"|| msg.type=="readstoragefilersp") {
     var cb = __idlookup[msg.id];
     delete __idlookup[msg.id];
     cb(msg.data);
