diff --git a/01/app.js b/01/app.js
index e69de29..1fc15b8 100644
--- a/01/app.js
+++ b/01/app.js
@@ -0,0 +1,6 @@
+function showTime() {
+    const time = (new Date()).toLocaleTimeString();
+    console.log(time);
+}
+
+showTime();
\ No newline at end of file
diff --git a/02/app.js b/02/app.js
index e69de29..8feb101 100644
--- a/02/app.js
+++ b/02/app.js
@@ -0,0 +1,6 @@
+
+function sayHello(name) {
+    console.log('Cześć ' + name + '!' );
+}
+
+sayHello('devmentor.pl');
\ No newline at end of file
diff --git a/03/app.js b/03/app.js
index e69de29..e3b5512 100644
--- a/03/app.js
+++ b/03/app.js
@@ -0,0 +1,11 @@
+const fn = function(stop) {
+    let sum = 0;
+    
+    for (let i = 1; i <= stop; i++) {
+        sum += i;
+    }
+    
+    return sum;
+}
+
+console.log(fn(4));
diff --git a/04/app.js b/04/app.js
index e69de29..cbc1bb8 100644
--- a/04/app.js
+++ b/04/app.js
@@ -0,0 +1,16 @@
+let idInterval;
+let counter = 0;
+
+
+const runTimer = function()  {
+    const time = (new Date()).toLocaleTimeString();
+    console.log(time);
+
+    counter++; 
+
+    if (counter === 5) {
+            clearInterval(idInterval);
+    }
+}
+
+idInterval = setInterval(runTimer, 1000);