RePen is a free, open-source screen annotation overlay for Windows 10/11. It allows teachers, presenters, tutorial creators, and remote teams to write, draw, highlight, and zoom directly on top of any active desktop application, PowerPoint slide, PDF, or video.

Key Features:

• Advanced Brushes: Standard Pen, Calligraphy brush, Highlighter, and fading Laser pointer.
• Presentation Focus Tools: Real-time Spotlight and screen Magnifier.
• Auto-Shapes: Rectangles, Circles, Lines, and Freehand Directional Arrows.
• Whiteboard Modes: Instantly swap to ruled notebook, grid, blackboard, or custom colored backgrounds.
• Export & Saving: Save multi-page whiteboard sessions and export them as high-quality PDFs.