diff --git a/start.py b/start.py
new file mode 100644
index 0000000..3c57ec9
--- /dev/null
+++ b/start.py
@@ -0,0 +1,36 @@
+import os
+import sys
+
+from PyQt6.QtWidgets import QApplication
+
+from core.app import StickyNoteApp
+
+
+def main() -> int:
+    os.environ["QT_AUTO_SCREEN_SCALE_FACTOR"] = "1"
+
+    QApplication.setQuitOnLastWindowClosed(False)
+
+    app = QApplication.instance()
+    if app is None:
+        app = QApplication(sys.argv)
+
+    app.setQuitLockEnabled(False)
+
+    existing = getattr(app, "_sticky_note_instance", None)
+    if existing is not None:
+        existing.raise_()
+        existing.activateWindow()
+        return 0
+
+    window = StickyNoteApp()
+
+    app._sticky_note_instance = window
+
+    window.show()
+
+    return app.exec()
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())