Add Watermark App is a lightweight desktop GUI app built with Tkinter and Pillow that makes watermarking photos simple and flexible. Add text or image watermarks, position them anywhere (corners, center, tiled), control opacity, scale and rotation, and preview changes in real time. Supports single-image edits and batch processing, and exports high-quality watermarked images in common formats (JPEG, PNG, WebP). Ideal for photographers, content creators, and anyone who needs to protect or brand images quickly.