diff --git a/package.json b/package.json
index 9a04f8629..ed2fff8ce 100644
--- a/package.json
+++ b/package.json
@@ -12,6 +12,7 @@
     "clean": "rimraf dist",
     "prebuild": "npm run clean",
     "dev": "webpack --progress --config webpack.config.js --mode development",
+    "watch": "webpack --watch --progress --config webpack.config.js --mode development",
     "build": "webpack --progress --config webpack.config.js --mode production",
     "gen_docs": "jsdoc -c jsdoc.conf.json src/*"
   },
diff --git a/src/index.mjs b/src/index.mjs
index b13ed27eb..913da4e29 100644
--- a/src/index.mjs
+++ b/src/index.mjs
@@ -10,6 +10,7 @@ import TFFaceMesh from './facemesh.mjs';
 import Reg from './ridgeReg.mjs';
 import ridgeRegWeighted from './ridgeWeightedReg.mjs';
 import ridgeRegThreaded from './ridgeRegThreaded.mjs';
+import RidgeRegXpln from './ridgeRegXpln.mjs';
 import util from './util.mjs';
 
 const webgazer = {};
@@ -18,6 +19,7 @@ webgazer.tracker.TFFaceMesh = TFFaceMesh;
 webgazer.reg = Reg;
 webgazer.reg.RidgeWeightedReg = ridgeRegWeighted.RidgeWeightedReg;
 webgazer.reg.RidgeRegThreaded = ridgeRegThreaded.RidgeRegThreaded;
+webgazer.reg.RidgeRegXpln = RidgeRegXpln;
 webgazer.util = util;
 webgazer.params = params;
 
@@ -57,7 +59,10 @@ var eventTypes = ['click', 'move'];
 //movelistener timeout clock parameters
 var moveClock = performance.now();
 //currently used tracker and regression models, defaults to clmtrackr and linear regression
+/* xpln.ai 2023-11-19: Disable default TFFaceMesh tracker, because we use our own faceTracker!
 var curTracker = new webgazer.tracker.TFFaceMesh();
+*/
+var curTracker = null; // xpln.ai 2023-11-19
 var regs = [new webgazer.reg.RidgeReg()];
 // var blinkDetector = new webgazer.BlinkDetector();
 
diff --git a/src/ridgeRegXpln.mjs b/src/ridgeRegXpln.mjs
new file mode 100644
index 000000000..57a685cbf
--- /dev/null
+++ b/src/ridgeRegXpln.mjs
@@ -0,0 +1,87 @@
+import util from './util.mjs';
+import util_regression from './util_regression.mjs';
+
+/**
+ * Constructor of RidgeRegXpln object,
+ * this object allow to perform ridge regression
+ * @constructor
+ */
+const RidgeRegXpln = function() {
+  this.init();
+};
+
+/**
+ * Initialize new arrays and initialize Kalman filter.
+ */
+RidgeRegXpln.prototype.init = util_regression.InitRegression
+
+/**
+ * Add given data from features
+ * @param {Array} features - features where extract data to add
+ * @param {Object} screenPos - The current screen point
+ * @param {Object} type - The type of performed action
+ */
+RidgeRegXpln.prototype.addData = function(features, screenPos, type) {
+  if (!features) return;
+  if (type === 'click') {
+    this.screenXClicksArray.push([screenPos[0]]);
+    this.screenYClicksArray.push([screenPos[1]]);
+    this.eyeFeaturesClicks.push(features);
+    delete this.xCoef;
+    delete this.yCoef;
+  } else if (type === 'move') {
+    throw new Error('Not implemented!!!');
+  }
+};
+
+/**
+ * Try to predict coordinates from pupil data
+ * after apply linear regression on data set
+ * @param {Array} features - The current user features features
+ * @returns {Object}
+ */
+RidgeRegXpln.prototype.predict = function(features) {
+  if (!features || this.eyeFeaturesClicks.length === 0) {
+    return null;
+  }
+
+  if (!this.xCoef || !this.yCoef) {
+    var screenXArray = this.screenXClicksArray.data;
+    var screenYArray = this.screenYClicksArray.data;
+    var eyeFeatures = this.eyeFeaturesClicks.data;
+    this.xCoef = util_regression.ridge(screenXArray, eyeFeatures, this.ridgeParameter);
+    this.yCoef = util_regression.ridge(screenYArray, eyeFeatures, this.ridgeParameter);
+  }
+
+  var predictedX = 0, predictedY = 0, cx = this.xCoef, cy = this.yCoef;
+  for(var i=0; i< features.length; i++) {
+    var f = features[i];
+    predictedX += f * cx[i];
+    predictedY += f * cy[i];
+  }
+
+  return {
+    x: Math.floor(predictedX),
+    y: Math.floor(predictedY)
+  };
+};
+
+RidgeRegXpln.prototype.setData = function() {
+  throw new Error('Not implemented!!!');
+};
+
+/**
+ * Return the data
+ * @returns {Array.<Object>|*}
+ */
+RidgeRegXpln.prototype.getData = function() {
+  throw new Error('Not implemented!!!');
+};
+
+/**
+ * The RidgeRegXpln object name
+ * @type {string}
+ */
+RidgeRegXpln.prototype.name = 'ridgeXpln';
+
+export default RidgeRegXpln;
diff --git a/src/util.mjs b/src/util.mjs
index 18bbdaecb..3c9b4c1ca 100644
--- a/src/util.mjs
+++ b/src/util.mjs
@@ -24,6 +24,20 @@ util.Eye = function(patch, imagex, imagey, width, height) {
     this.height = height;
 };
 
+// xpln.ai 2024-02-26: normalize pixel values between 0 and 1
+util.normalize = function(arr, digits) {
+    var min = Infinity, max = -Infinity, precision = Math.pow(10, digits);
+    for (var i=0, imax=arr.length; i<imax; i++) {
+        if (min > arr[i]) min = arr[i];
+        if (max < arr[i]) max = arr[i];                
+    }
+    var range = max - min;
+    if (!range) return;
+    for (var i=0, imax=arr.length; i<imax; i++) {
+        arr[i] = Math.round(precision * (arr[i] - min) / range) / precision;
+    }
+};
+
 /**
  * Compute eyes size as gray histogram
  * @param {Object} eyes - The eyes where looking for gray histogram
@@ -35,9 +49,12 @@ util.getEyeFeats = function(eyes) {
         let gray = this.grayscale(resized.data, resized.width, resized.height);
         let hist = [];
         this.equalizeHistogram(gray, 5, hist);
+        // xpln.ai 2024-02-26: normalize pixel values between 0 and 1
+        if (eyes.normalize) this.normalize(hist, 3);
         return hist;
     };
-
+    // xpln.ai 2023-11-27: simply override data for ridge regression
+    if (eyes.ridgeRegData) return eyes.ridgeRegData;
     if (webgazer.params.trackEye == 'left') {
         return process(eyes.left);
     }
@@ -45,7 +62,8 @@ util.getEyeFeats = function(eyes) {
         return process(eyes.right);
     }
     else {
-        return [].concat(process(eyes.left), process(eyes.right));
+        // xpln.ai 2024-02-09: add extra data for ridge regression
+        return [].concat(process(eyes.left), process(eyes.right), eyes.ridgeRegExtra);
     }
 }
 
diff --git a/webpack.config.js b/webpack.config.js
index e0c0d1129..b2fc0149a 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -46,10 +46,14 @@ const varConfig = {
 			events: {
 				onEnd: {
 					copy: [
+						/* xpln.ai 2023-11-19: Disable useless copy to ./www/
 			            { source: './dist/webgazer.js', destination: './www/' },
 			            { source: './dist/webgazer.js.map', destination: './www/' },
 			            { source: './dist/webgazer.js', destination: './www/data/src/' },
 			            { source: './dist/webgazer.js.map', destination: './www/data/src/' },
+						*/
+						// xpln.ai 2023-11-19: Instead we copy to our own chrome extension
+						{ source: './dist/webgazer.js', destination: '../xpln.ai/scripts_crea/chrome_extension/ext/webgazer/webgazer.js', options: { overwrite: true } },
 			        ],
 				},
 			},