FlashMark

Draw. Fade. Focus.
A lightweight screen annotation tool with auto-fading strokes.
Built for remote meetings, teaching, and screen sharing.

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Quick Start

1. Download FlashMark.exe from Releases (38MB, no install needed)
2. Launch — double-click, FlashMark hides in your system tray
3. Annotate — press Ctrl+Shift+D, draw on screen, press again to exit

That's it. No setup, no config, no dependencies.

Windows SmartScreen warning: Since the exe is not code-signed, Windows may show a "protected your PC" warning. Click "More info" → "Run anyway" to proceed.

Use Cases

Scenario	How FlashMark helps
Remote meetings	Circle key data points, draw arrows to guide attention — strokes fade so your screen stays clean
Teaching & demos	Annotate live code, diagrams, or slides without switching apps
Code reviews	Highlight lines, draw connections between components during screen share
Presentations	Emphasize slides in real-time, annotations disappear before the next topic
Bug reports	Quickly mark UI issues on screen while walking through reproduction steps

Why FlashMark?

Most annotation tools are designed for screenshots — you take a snapshot, mark it up, save it. FlashMark is designed for live screen — you draw directly on your desktop in real-time.

	Traditional tools	FlashMark
Workflow	Screenshot → annotate → share	Draw directly on screen
Persistence	Annotations stay forever	Auto-fade after 3 seconds
Switching	Open app, select area, draw	One hotkey, draw anywhere
Screen clutter	Builds up over time	Always clean
During meetings	Awkward alt-tab to tool	Instant overlay, zero disruption

How It Works

stateDiagram-v2
    [*] --> Idle: Launch
    Idle --> Annotating: Ctrl+Shift+D
    Annotating --> Idle: Ctrl+Shift+D

    state Idle {
        [*] --> Background
        Background: Hidden in system tray, zero interference
    }

    state Annotating {
        [*] --> Draw
        Draw: Fullscreen overlay with blue glow border
        Draw: Left click to draw, strokes auto-fade
        Draw: Right click for pie menu
    }

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Features

Feature	Description
Auto-fading	Strokes fade away automatically (2s delay + 1s fade)
5 Tools	Pen, Arrow, Rectangle, Ellipse, Eraser
5 Colors	Red, Blue, Green, Yellow (default), White
Pie Menu	Right-click radial menu for quick tool/color switching
Global Hotkey	Ctrl+Shift+D toggles annotation mode from anywhere
Visual Feedback	Blue gradient glow border + status bar when active
System Tray	Runs silently in tray, right-click to toggle or exit
Undo / Clear	Ctrl+Z undo, Ctrl+Shift+Z clear all
Stroke Width	Scroll wheel to adjust (1px ~ 20px, default 5px)
Stealth Mode	Hidden from Alt+Tab, invisible when inactive

Keyboard Shortcuts

Only work in annotation mode (after Ctrl+Shift+D)

Shortcut	Action
Ctrl+Shift+D	Toggle annotation mode (global)
Right Click	Open Pie Menu
Scroll Wheel	Adjust stroke width
Ctrl+Z / Ctrl+Shift+Z	Undo / Clear all
1 2 3 4 5	Pen / Arrow / Rect / Ellipse / Eraser
Q W E R T	Red / Blue / Green / Yellow / White

Tech Stack

• C# / .NET 10
• Avalonia UI 12
• Skia-based 2D rendering
• Win32 P/Invoke (global keyboard hook, window styles)

Build from Source

# Run in development
dotnet build
dotnet run --project src/FlashMark

# Build portable exe (no .NET required to run)
dotnet publish src/FlashMark -c Release -r win-x64 --self-contained true \
  -p:PublishSingleFile=true -p:PublishTrimmed=true -p:TrimMode=full -o publish

Roadmap

• P0 — Windows annotation with auto-fade
• P1 — Number markers ①②③, magnifier, fade/permanent toggle
• P2 — macOS support, text annotations, spotlight, custom hotkeys

License

MIT