diff --git a/src/main.rs b/src/main.rs
index e7a11a9..2a8bbf6 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,19 @@
+use gtk::prelude::*;
+use gtk::{Application, ApplicationWindow};
+
+const APP_ID: &'static str = "org.gtk-rs.Gamarjoba";
+
 fn main() {
-    println!("Hello, world!");
+    let app = Application::builder().application_id(APP_ID).build();
+    app.connect_activate(build_ui);
+    app.run();
+}
+
+fn build_ui(app: &Application) {
+    let window = ApplicationWindow::builder()
+        .application(app)
+        .title("Gamarjoba from GTK4")
+        .build();
+
+    window.present();
 }