diff --git a/apps/phystrax/app.js b/apps/phystrax/app.js
new file mode 100644
index 000000000..4576a9114
--- /dev/null
+++ b/apps/phystrax/app.js
@@ -0,0 +1,113 @@
+let isMeasuring = false;
+let currentHeartRate = null;
+let lcdTimeout;
+let logData = [];
+
+function startMeasure() {
+    isMeasuring = true;
+    Bangle.setLCDTimeout(0);
+    lcdTimeout = setTimeout(() => {
+        Bangle.setLCDTimeout(50);
+    }, 50000);
+
+    setTimeout(() => {
+        Bangle.setHRMPower(1);
+        Bangle.on('HRM', handleHeartRate);
+        Bangle.beep(400, 1000); // Buzz to indicate measurement start
+        drawScreen();
+    }, 500);
+}
+
+function stopMeasure() {
+    isMeasuring = false;
+    clearTimeout(lcdTimeout);
+    Bangle.setLCDTimeout(10);
+    Bangle.setHRMPower(0);
+    Bangle.removeAllListeners('HRM');
+    saveDataToCSV(); // Save data to CSV when measurement stops
+    Bangle.beep(400, 800); // Buzz to indicate measurement stop
+    drawScreen();
+}
+
+function handleHeartRate(hrm) {
+    if (hrm.confidence > 90) {
+        currentHeartRate = hrm.bpm;
+        var date = new Date();
+        var dateStr = require("locale").date(date);
+        var timeStr = require("locale").time(date, 1);
+        var timestamp = dateStr + " " + timeStr; // Concatenate date and time
+        logData.push({ timestamp: timestamp, heartRate: currentHeartRate });
+        drawScreen();
+    }
+}
+
+
+function drawScreen(message) {
+    g.clear(); // Clear the display
+
+    // Set the background color
+    g.setColor('#95E7FF'); 
+
+    // Fill the entire display with the background color
+    g.fillRect(0, 0, g.getWidth(), g.getHeight());
+
+    // Set font and alignment for drawing text
+    g.setFontAlign(0, 0);
+    g.setFont('Vector', 15); 
+
+    // Draw the title
+    g.setColor('#000000'); // Set text color to black
+    g.drawString('Heart Rate Monitor', g.getWidth() / 2, 10);
+
+    if (isMeasuring) {
+        // Draw measuring status
+        g.setFont('6x8', 2);
+        g.drawString('Measuring...', g.getWidth() / 2, g.getHeight() / 2 - 10);
+
+        // Draw current heart rate if available
+        g.setFont('6x8', 4);
+        if (currentHeartRate !== null) {
+            g.drawString(currentHeartRate.toString(), g.getWidth() / 2, g.getHeight() / 2 + 20);
+            g.setFont('6x8', 1.6);
+            g.drawString(' BPM', g.getWidth() / 2 + 42, g.getHeight() / 2 + 20);
+        }
+
+        // Draw instructions
+        g.setFont('6x8', 1.5);
+        g.drawString('Press button to stop', g.getWidth() / 2, g.getHeight() / 2 + 42);
+    } else {
+        // Draw last heart rate
+        g.setFont('Vector', 12);
+        g.drawString('Last Heart Rate:', g.getWidth() / 2, g.getHeight() / 2 - 20);
+        if (currentHeartRate !== null && currentHeartRate > 0) {
+            g.setFont('6x8', 4);
+            g.drawString(currentHeartRate.toString(), g.getWidth() / 2, g.getHeight() / 2 + 10);
+        } else {
+            g.setFont('6x8', 2);
+            g.drawString('No data', g.getWidth() / 2, g.getHeight() / 2 + 10);
+            g.setFont('6x8', 1);
+            g.drawString(message || 'Press button to start', g.getWidth() / 2, g.getHeight() / 2 + 30);
+        }
+    }
+
+    // Update the display
+    g.flip();
+}
+
+function saveDataToCSV() {
+    let csvContent = "Timestamp,Heart Rate\n";
+    logData.forEach(entry => {
+        csvContent += `${entry.timestamp},${entry.heartRate}\n`;
+    });
+    require("Storage").write("heart_rate_data.csv", csvContent);
+}
+
+setWatch(function() {
+    if (!isMeasuring) {
+        startMeasure();
+    } else {
+        stopMeasure();
+    }
+}, BTN1, { repeat: true, edge: 'rising' });
+
+drawScreen();