diff --git a/apps/calendar/interface.html b/apps/calendar/interface.html
index ea64632f8..71b9a153c 100644
--- a/apps/calendar/interface.html
+++ b/apps/calendar/interface.html
@@ -178,9 +178,8 @@ function getData() {
     })()\n`, contents => {
       const fileNames = JSON.parse(contents);
       if (fileNames.length > 0) {
-        Util.readStorage('calendar.days.json',data=>{
-          holidays = JSON.parse(data || "[]") || [];
-
+        Util.readStorageJSON('calendar.days.json',data=>{
+          holidays = data || [];
           Util.hideModal();
           render();
         });
diff --git a/apps/espruinoterm/interface.html b/apps/espruinoterm/interface.html
index 660b3a86c..6ff7b7da5 100644
--- a/apps/espruinoterm/interface.html
+++ b/apps/espruinoterm/interface.html
@@ -83,11 +83,8 @@
 
       function onInit() {
         Util.showModal("Loading...");
-        Util.readStorage("espruinoterm.json", function(j) {
+        Util.readStorageJSON("espruinoterm.json", function(options) {
           Util.hideModal();
-          try {
-            options = JSON.parse(j);
-          } catch (e) {}
           if (!Array.isArray(options)) setDefaults();
           refresh();
         });
diff --git a/apps/grocery/interface.html b/apps/grocery/interface.html
index 0c8df1e86..c424643a8 100644
--- a/apps/grocery/interface.html
+++ b/apps/grocery/interface.html
@@ -76,11 +76,11 @@
       function getData() {
         // show loading window
         Util.showModal("Loading...");
-        Util.readStorage('grocery_list.json', data=>{
+        Util.readStorageJSON('grocery_list.json', data=>{
           // remove window
           Util.hideModal();
 
-          settings = JSON.parse(data || '{"products": []}');
+          settings = data || {"products": []};
           products = settings.products;
           renderProducts();
         });
diff --git a/apps/guitarsongs/manage_songs.html b/apps/guitarsongs/manage_songs.html
index 9280d8d96..bdcab53af 100644
--- a/apps/guitarsongs/manage_songs.html
+++ b/apps/guitarsongs/manage_songs.html
@@ -211,9 +211,9 @@
         this.editSong = song;
       },
       loadSongs: function () {
-        Util.readStorage('guitar_songs.json', (contents) => {
+        Util.readStorageJSON('guitar_songs.json', (contents) => {
           this.songsState = 'loaded';
-          this.localSongs = JSON.parse(contents) || [];
+          this.localSongs = contents || [];
           this.watchSongs = JSON.parse(JSON.stringify(this.localSongs));
         });
         window.setTimeout(() => {
diff --git a/apps/mylocation/interface.html b/apps/mylocation/interface.html
index 79a122bf7..1bd3129ee 100644
--- a/apps/mylocation/interface.html
+++ b/apps/mylocation/interface.html
@@ -98,11 +98,10 @@
 
       function onInit() {
         // read existing location
-        Util.readStorage("mylocation.json", function(data) {
+        Util.readStorageJSON("mylocation.json", function(data) {
           if (data===undefined) return; // no file
           try {
-            var j = JSON.parse(data);
-            setPosition(j);
+            setPosition(data);
           } catch (e) {
             console.error(e);
           }
diff --git a/apps/noteify/interface.html b/apps/noteify/interface.html
index 4d7974ad9..6635ff5ed 100644
--- a/apps/noteify/interface.html
+++ b/apps/noteify/interface.html
@@ -26,8 +26,8 @@ function disableFormInput() {
 function getData() {
   // show loading window
   Util.showModal("Loading...");
-  Util.readStorage(`noteify.json`,data=>{
-    notes = JSON.parse(data || "[]");
+  Util.readStorageJSON(`noteify.json`,data=>{
+    notes = data || [];
 
     // remove window
     Util.hideModal();
diff --git a/apps/openstmap/interface.html b/apps/openstmap/interface.html
index 9e22c57e4..938a8ea32 100644
--- a/apps/openstmap/interface.html
+++ b/apps/openstmap/interface.html
@@ -150,15 +150,9 @@ TODO:
           files.trim().split(",").forEach(filename => {
             if (filename=="") return;
             promise = promise.then(() => new Promise(resolve => {
-              Util.readStorage(filename, fileContents => {
-                console.log(filename + " => " + fileContents);
+              Util.readStorageJSON(filename, mapInfo => {
+                console.log(filename + " => " + mapInfo);
                 let mapNumber = filename.match(/\d+/)[0]; // figure out what map number we are
-                let mapInfo;
-                try {
-                  mapInfo = JSON.parse(fileContents);
-                } catch (e) {
-                  console.error(e);
-                }
                 loadedMaps[mapNumber] = mapInfo;
                 if (mapInfo!==undefined) {
                   let latlon = L.latLng(mapInfo.lat, mapInfo.lon);
diff --git a/apps/owmweather/interface.html b/apps/owmweather/interface.html
index 3f9467a83..205035749 100644
--- a/apps/owmweather/interface.html
+++ b/apps/owmweather/interface.html
@@ -2,35 +2,34 @@
   <head>
     <link rel="stylesheet" href="../../css/spectre.min.css">
   </head>
-  <body>   
+  <body>
     <h3>Set OpenWeatherMap (OWM) API key</h3>
     <p><input id="apikey" onkeyup="checkInput()"  style="width:90%; margin: 3px"></input><button id="upload" class="btn btn-primary">Save key</button></p>
-    
+
     <h4>Where to get your personal API key?</h4>
     <p>Go to <a href="https://home.openweathermap.org/users/sign_up">https://home.openweathermap.org/users/sign_up</a> and sign up for a free account.<br>
     After registration you can login and optain your personal API key.</p>
-    
+
 
     <script src="../../core/lib/interface.js"></script>
 
     <script>
-    
+
        function checkInput() {
-        if(document.getElementById("apikey").value==="") { 
-                document.getElementById('upload').disabled = true; 
-            } else { 
+        if(document.getElementById("apikey").value==="") {
+                document.getElementById('upload').disabled = true;
+            } else {
                 document.getElementById('upload').disabled = false;
             }
         }
         checkInput();
-    
+
         var settings = {};
         function onInit(){
           console.log("Loading settings from BangleJs...");
           try {
-            Util.readStorage("owmweather.json", data=>{
-              if(data.length > 0){
-                settings = JSON.parse(data);
+            Util.readStorageJSON("owmweather.json", settings=>{
+              if("settings){
                 console.log("Got settings", settings);
                 document.getElementById("apikey").value = settings.apikey;
                 console.log("Loaded apikey from BangleJs.");
@@ -41,9 +40,9 @@
               console.log("(Warning) Could not load apikey from BangleJs.");
               console.log(ex);
           }
-        
+
         }
-        
+
         document.getElementById("upload").addEventListener("click", function() {
             try {
               settings.apikey = document.getElementById("apikey").value;
diff --git a/apps/powermanager/interface.html b/apps/powermanager/interface.html
index 2cab4561a..51c31cc81 100644
--- a/apps/powermanager/interface.html
+++ b/apps/powermanager/interface.html
@@ -2,7 +2,7 @@
   <head>
     <link rel="stylesheet" href="../../css/spectre.min.css">
 
-    <style> 
+    <style>
       .table_wrapper{
         display: block;
         overflow-x: auto;
@@ -101,11 +101,9 @@ function viewDeferredTable(filename) {
   Puck.eval(`require("Storage").list("powermanager.def.json").length > 0`, (f)=>{
     if (f) {
       Util.showModal("Reading summarized info...");
-      Util.readStorage(
-        filename, data => {
+      Util.readStorageJSON(
+        filename, parsed => {
           Util.hideModal();
-          let parsed = JSON.parse(data);
-          
           let sum = 0;
           let rows = [];
           for (var i in parsed.deferred) {
@@ -128,7 +126,7 @@ function viewDeferredTable(filename) {
             <button class="btn btn-primary" id="back" style="float: right;margin-right: 5px;margin-left: 10px;">Back</button>
             <div>
               This are functions used in timeouts and intervals and their accumulated execution times. Recorded in a time span of <b>${timeFormat(duration)}</b>. Timeouts/intervals have run for <b>${timeFormat(sum)} (${(sum/duration*100).toFixed(2)}%)</b>. Percentages are calculated from summarized timeout/interval running time.
-            </div>           
+            </div>
 
             <div class="table_wrapper">
 
@@ -181,13 +179,12 @@ function viewHardwareTable(filename) {
   Puck.eval(`require("Storage").list("powermanager.hw.json").length > 0`, (f)=>{
     if (f) {
       Util.showModal("Reading hardware info...");
-      Util.readStorage(
-        filename, data => {
+      Util.readStorageJSON(
+        filename, parsed => {
           Util.hideModal();
-          let parsed = JSON.parse(data);
           console.log("Hardware", parsed);
           let duration = parsed.saved - parsed.start;
-          
+
           let rows = [];
           for (var i in parsed.power) {
             rows.push({func: i, time: parsed.power[i]});
@@ -244,7 +241,7 @@ function viewDetailsTable(filename) {
   Util.readStorageFile(
     filename, data => {
       Util.hideModal();
-      
+
       var htmlOverview = `<h1>Detailed logging</h1>
       <button class="btn btn-primary" id="back" style="float: right;margin-right: 5px;">Back</button>
       <div>
diff --git a/apps/rep/interface.html b/apps/rep/interface.html
index 99ec1c890..e14fea4c9 100644
--- a/apps/rep/interface.html
+++ b/apps/rep/interface.html
@@ -101,10 +101,8 @@ function getData() {
   uploadBtn.disabled = true;
 
   Util.showModal("Loading...");
-  Util.readStorage(repJson, data => {
+  Util.readStorageJSON(repJson, reps => {
     Util.hideModal();
-
-    reps = JSON.parse(data);
     for(const rep of reps){
       renderRep(rep);
     }
diff --git a/apps/sched/interface.html b/apps/sched/interface.html
index 53b443371..68547aa7e 100644
--- a/apps/sched/interface.html
+++ b/apps/sched/interface.html
@@ -265,11 +265,11 @@ function addTimer() {
 
 function getData() {
   Util.showModal("Loading...");
-  Util.readStorage('sched.json',data=>{
-    alarms = JSON.parse(data || "[]") || [];
+  Util.readStorageJSON('sched.json',data=>{
+    alarms = data || [];
 
-    Util.readStorage('sched.settings.json',data=>{
-      schedSettings = JSON.parse(data || "{}") || {};
+    Util.readStorageJSON('sched.settings.json',data=>{
+      schedSettings = data || {};
       Util.hideModal();
       alarms.sort((a, b) => {
         let x;
diff --git a/apps/sleepphasealarm/interface.html b/apps/sleepphasealarm/interface.html
index 8c8cea990..9b2004904 100644
--- a/apps/sleepphasealarm/interface.html
+++ b/apps/sleepphasealarm/interface.html
@@ -25,8 +25,8 @@ function getData() {
   // show loading window
   Util.showModal("Loading...");
   // get the data
-  Util.readStorage('sleepphasealarm.json',data=>{
-    let logs = JSON.parse(data || "{}")?.logs || [];
+  Util.readStorageJSON('sleepphasealarm.json',data=>{
+    let logs = (data || {})?.logs || [];
     // remove window
     Util.hideModal();
 
diff --git a/apps/tinycmc/interface.html b/apps/tinycmc/interface.html
index 2a9e7824b..9f774d1b8 100644
--- a/apps/tinycmc/interface.html
+++ b/apps/tinycmc/interface.html
@@ -2,35 +2,35 @@
   <head>
     <link rel="stylesheet" href="../../css/spectre.min.css">
   </head>
-  <body>   
+  <body>
     <h3>Set Coinmarketcap API key</h3>
     <p><input id="apikey" onkeyup="checkInput()"  style="width:90%; margin: 3px"></input><button id="upload" class="btn btn-primary">Save key</button></p>
-    
+
     <h4>Where to get your personal API key?</h4>
     <p>Go to <a href="https://coinmarketcap.com/api/">https://coinmarketcap.com/api/</a> and sign up for a free account.<br>
     After registration you can login and obtain your personal API key.</p>
-    
+
 
     <script src="../../core/lib/interface.js"></script>
 
     <script>
-    
+
        function checkInput() {
-        if(document.getElementById("apikey").value==="") { 
-                document.getElementById('upload').disabled = true; 
-            } else { 
+        if(document.getElementById("apikey").value==="") {
+                document.getElementById('upload').disabled = true;
+            } else {
                 document.getElementById('upload').disabled = false;
             }
         }
         checkInput();
-    
+
         var settings = {};
         function onInit(){
           console.log("Loading settings from BangleJs...");
           try {
-            Util.readStorage("tinycmc.json", data=>{
-              if(data.length > 0){
-                settings = JSON.parse(data);
+            Util.readStorageJSON("tinycmc.json", data=>{
+              if(data){
+                settings = data;
                 console.log("Got settings", settings);
                 document.getElementById("apikey").value = settings.apikey;
                 console.log("Loaded apikey from BangleJs.");
@@ -41,9 +41,9 @@
               console.log("(Warning) Could not load apikey from BangleJs.");
               console.log(ex);
           }
-        
+
         }
-        
+
         document.getElementById("upload").addEventListener("click", function() {
             try {
               settings.apikey = document.getElementById("apikey").value;
diff --git a/core b/core
index 4422e4a3e..c97b7851f 160000
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit 4422e4a3e808c99e540dc86ac1e3cab0ccb23a82
+Subproject commit c97b7851f50cfff4e898c2264a337a17085ce463