Documentation

Everything you need to know to master HoverScribble

Introduction

HoverScribble is a professional screen annotation tool for Windows that creates a transparent overlay for drawing, highlighting, and presenting on top of any application. Whether you're a teacher, presenter, content creator, or just need to annotate your screen, HoverScribble provides all the tools you need.

System Requirements: Windows 10 or later, .NET 8 Runtime (included in installer)

Key Features

  • Draw on top of any application with pen, highlighter, and shape tools
  • Pressure-sensitive stylus support for natural drawing
  • Laser pointer and spotlight for presentations
  • Whiteboard and blackboard modes
  • Screenshot capture with annotations
  • Built-in calculator with 4 modes
  • Customizable keyboard shortcuts

Quick Start

Get started with HoverScribble in just a few steps:

1. Launch HoverScribble

After installation, launch HoverScribble from the Start menu or desktop shortcut. The floating toolbar will appear on your screen.

2. Select a Tool

Click on any tool in the toolbar to select it. The pen tool is selected by default.

3. Start Drawing

Click and drag anywhere on the screen to draw. Your strokes will appear on top of all other windows.

4. Switch to Mouse Mode

When you need to interact with your applications normally, click the mouse icon or press Ctrl+Shift+M to enable click-through mode.

Pro Tip: Press Ctrl+Shift+P at any time to toggle HoverScribble on/off. This is the global hotkey that works even when HoverScribble is minimized.

Essential Shortcuts & Tips

ESC Key Behavior:

  • If whiteboard/blackboard is active → Turns it off
  • If using any drawing tool → Switches to Mouse mode
  • If toolbar is visible → Enter mini mode (small floating icon)
  • If in mini mode → Hides to system tray
Adjust stroke size Mouse Scroll
Quick color 1-8 1-8 keys
Undo last stroke Ctrl+Z
Exit/Back ESC

Colors & Color Picker

HoverScribble provides multiple ways to select and customize colors for your annotations.

Quick Color Selection

The toolbar displays 8 quick-access color buttons. Click any color to select it immediately, or press number keys 1-8 to select colors by position.

Default Colors Position
■ Black1
■ White2
■ Red3
■ Orange4
■ Yellow5
■ Green6
■ Blue7
■ Purple8

Advanced Color Picker

Click the color picker button (palette icon) to open the full color picker with:

  • Color Spectrum: Click anywhere on the gradient to select a color
  • Hue Slider: Drag to change the base hue
  • RGB Sliders: Fine-tune Red, Green, Blue values (0-255)
  • Hex Input: Enter exact hex color codes (e.g., #FF5733)
  • Recent Colors: Quick access to recently used colors

Eyedropper Tool

Pick any color from anywhere on your screen:

  1. Open the Color Picker
  2. Click the eyedropper icon
  3. Move your cursor over any pixel on screen
  4. Click to capture that color
  5. Press ESC to cancel

Tip: Customize the 8 default toolbar colors in Settings → Default Colors. Your choices are saved and persist between sessions.

Drawing Tools

HoverScribble provides a variety of drawing tools for different annotation needs.

Pen

Standard drawing tool

The primary drawing tool with smooth, pressure-sensitive strokes. Perfect for writing and freehand drawing.

Ctrl+Shift+D

Highlighter

Semi-transparent marker

Semi-transparent strokes for highlighting text and important areas without obscuring content.

Ctrl+Shift+H

Calligraphy

Angled brush tip

Creates beautiful calligraphic strokes with an angled tip that varies in thickness based on direction.

Settings → Enable

Crayon

Textured crayon effect

Simulates a crayon with textured, slightly uneven strokes for a hand-drawn artistic feel.

Settings → Enable

Spray Paint

Spray can effect

Creates a spray paint effect with scattered dots, perfect for graffiti-style annotations.

Settings → Enable

Eraser

Remove strokes

Removes strokes by touching them. Works on any stroke type including shapes and text.

Ctrl+Shift+E

Pen Tool

The Pen is HoverScribble's primary drawing tool, designed for smooth, natural strokes.

Features

  • Pressure Sensitivity: When using a stylus, stroke thickness varies with pressure
  • Smooth Drawing: Quadratic Bezier curves smooth out jagged strokes
  • Color Selection: Choose from preset colors or use the custom color picker
  • Adjustable Thickness: Use the slider to change stroke width

Settings

Setting Description Default
Pressure Sensitivity Enable/disable pressure-based thickness Enabled
Sensitivity Strength How much pressure affects thickness (0-200%) 100%
Smooth Drawing Apply smoothing to strokes Enabled
Smooth Handwriting Extra smoothing for mouse users Disabled

Highlighter

The highlighter creates semi-transparent strokes that allow underlying content to remain visible. It's perfect for marking up documents, emphasizing text, or drawing attention to specific areas.

  • 50% opacity for see-through highlighting
  • Works great with bright colors like yellow and green
  • Supports pressure sensitivity for varying opacity

Shape Tools

Create perfect geometric shapes by clicking and dragging. Hold Shift while drawing for proportional shapes (perfect circles and squares).

Rectangle

Draw rectangles and squares. Hold Shift for perfect squares.

Ctrl+Shift+R

Ellipse

Draw ellipses and circles. Hold Shift for perfect circles.

Ctrl+Shift+O

Triangle

Draw triangles pointing in the direction you drag.

Settings → Enable

Lines & Arrows

Use lines and arrows to point out important elements or show connections between items.

Line

Draw straight lines between two points.

Ctrl+Shift+L

Arrow

Draw arrows that point from start to end position.

Ctrl+Shift+A

Advanced Shapes

HoverScribble includes a variety of advanced shapes for more complex annotations. Enable them in Settings → Enabled Tools.

Shape Description
Diamond Rotated square shape
Star 5-pointed star
Pentagon 5-sided polygon
Hexagon 6-sided polygon
Heart Heart shape
Cloud Cloud/thought bubble
Lightning Lightning bolt
Checkmark Checkmark/tick symbol
X Mark X/cross symbol
Plus Plus sign
Minus Minus sign
Block Arrow Thick block arrow
Speech Bubble Comic-style speech bubble

Text Tool

Add text annotations anywhere on the screen. Click to place text, then type your message.

  • Click anywhere to place text
  • Customizable font family and size
  • Drag to reposition after placing
  • Double-click to edit existing text
Setting Description Default
Font Family The font used for text Segoe UI
Font Size Size of the text in points 24

Laser Pointer

A bright, attention-grabbing pointer that follows your cursor. Perfect for presentations when you need to point out specific items without leaving permanent marks.

  • Bright red glowing dot visible on any background
  • Click-through enabled - interact with apps while using
  • Adjustable size in settings
Setting Description Default
Laser Size Diameter of the laser pointer in pixels 24

Spotlight

Dims the entire screen except for a circular area around your cursor. Use this to focus your audience's attention on a specific area.

  • Darkens screen to 70% opacity outside spotlight
  • Adjustable spotlight radius
  • Click-through enabled for interaction
Setting Description Default
Spotlight Size Radius of the spotlight in pixels 100

Ruler

Place on-screen rulers to draw straight lines, measure distances, or align elements. You can have up to 6 rulers on screen at once.

  • Click to place rulers anywhere on screen
  • Drag to move, drag ends to resize
  • Rotate handles for angle adjustment
  • Snap to angles (configurable)
  • Draw along ruler edge for straight lines
  • Double-click to remove a ruler
Setting Description Default
Snap Angle Angle increment for snapping (0 = off) 15°
Default Length Initial ruler length in pixels 400

Fading Ink

When enabled, your strokes will gradually fade away after a set duration. This is perfect for presentations where you want to draw attention to something temporarily.

Toggle fading ink on/off with Ctrl+Shift+F or click the fading ink button in the toolbar.

Setting Description Default
Fading Duration How long strokes take to fade (milliseconds) 4000 (4 seconds)

Whiteboard & Blackboard

Create a colored background for drawing. Toggle between white and black colors, and choose how much of your screen to cover.

Color Options

  • Whiteboard (Ctrl+Shift+W): White background, great for teaching
  • Blackboard (Ctrl+Shift+B): Dark background, easier on eyes
  • Your color preference is remembered between sessions

Coverage Options

Click the dropdown arrow next to the board button to access coverage options:

Option Description
Single Screen Board covers only the monitor where the toolbar is located
All Screens Board covers all monitors (default)
Choose Area Drag to select a custom rectangular area to cover

Usage

  • Click the board button to toggle on/off using your last selected color
  • Click the dropdown arrow to switch colors or change coverage area
  • The button icon shows your current color selection (white or black)

Screenshot

Capture screenshots with your annotations included. Choose between capturing the entire screen, a single monitor, or a selected region.

Mode Description
Current Screen Captures the monitor where the toolbar is located
All Screens Captures all monitors as one image
Region Select Draw a rectangle to capture a specific area

Screenshots are saved to your Pictures folder by default, or you can choose a save location each time.

Calculator

A built-in calculator with four modes: Basic, Scientific, Graphing, and Matrix. Access it quickly without leaving HoverScribble.

Basic Calculator

Standard calculator for everyday arithmetic:

  • Operations: +, -, ×, ÷, %
  • Memory Functions: MC (clear), MR (recall), M+ (add to memory), M- (subtract from memory)
  • Clear: C (clear entry), AC (all clear)
  • Keyboard: Type numbers and operators directly

Scientific Calculator

Advanced functions for scientific and engineering calculations:

Category Functions
Trigonometry sin, cos, tan, asin, acos, atan, sinh, cosh, tanh
Logarithms log (base 10), ln (natural log), log₂
Powers & Roots x², x³, xⁿ, √, ³√, ⁿ√, 10ˣ, eˣ
Other |x| (absolute), n! (factorial), 1/x (reciprocal), +/- (negate)
Constants π (pi = 3.14159...), e (Euler = 2.71828...)

RAD/DEG Toggle: Switch between radians and degrees for trigonometric functions. Default is Degrees.

Graphing Calculator

Visualize mathematical functions with an interactive graph:

  • Plot Functions: Enter equations like sin(x), x^2, 2*x+1
  • Multiple Graphs: Add multiple functions with different colors
  • Zoom: Scroll to zoom in/out on the graph
  • Pan: Click and drag to move around the coordinate system
  • Derivative (f'): Toggle to show the derivative of your function
  • Integral (∫f): Toggle to show the integral/antiderivative
  • Color Picker: Customize each function's graph color
  • Trace: Hover over graph to see (x, y) coordinates

Supported Syntax: Use x as the variable. Supported: +, -, *, /, ^ (power), sqrt(), sin(), cos(), tan(), log(), ln(), abs(), pi, e

Matrix Calculator

Perform operations on matrices up to 4×4:

Operation Description
Determinant (det) Calculate the determinant of a square matrix
Inverse (A⁻¹) Find the inverse matrix (if determinant ≠ 0)
Transpose (Aᵀ) Swap rows and columns of the matrix
Size Selection Choose matrix dimensions: 2×2, 3×3, or 4×4

Calculator Settings

Setting Description Default
Default Mode Which calculator mode opens by default Scientific

Story Mode

Automatically capture screenshots at regular intervals to create a visual timeline of your work. Great for creating tutorials or documenting processes.

  • Automatic periodic screenshots
  • Smart duplicate detection - skips similar frames
  • Optional PDF generation at end
Setting Description Default
Capture Interval Seconds between captures 10
Max Duration Maximum recording time in minutes 60
Similarity Threshold How similar frames need to be to skip (0.98-1.0) 0.998
Generate PDF Create PDF at end of recording Yes

Settings

Access settings by clicking the gear icon in the toolbar. Settings are saved automatically to %APPDATA%/HoverScribble/settings.json.

General Settings

Setting Description Default
Start with Windows Launch HoverScribble when Windows starts. Adds entry to Windows startup registry. Off
Start Minimized Start hidden in system tray instead of showing toolbar Off
Minimize to Tray When minimized, hide to system tray instead of taskbar On
Show Status Indicator Display current tool name in corner of screen On

Toolbar Settings

Setting Range Effect Default
Toolbar Opacity 0% - 100% Lower = more transparent toolbar. 0% makes toolbar invisible (not recommended) 95%
Compact Mode On/Off On = smaller buttons, fits more tools. Off = larger buttons, easier to click On
Vertical Toolbar On/Off On = toolbar arranged in column. Off = toolbar arranged in row Off
Dual Row Mode On/Off On = tools in 2 rows/columns (compact). Off = single row/column (longer) On
Icon Scale 75% - 150% Scales entire toolbar. 75% = small for large monitors. 150% = large for touch/accessibility 100%

Drawing Settings

Setting Range Effect Default
Default Color Any color Color selected when HoverScribble starts Black (#000000)
Default Thickness 1 - 50 px Stroke width on startup. Larger = thicker strokes 4
Default Tool Any tool Tool selected when HoverScribble starts Pen
Pressure Sensitivity On/Off On = stylus pressure affects stroke width. Off = constant width On
Pressure Strength 0% - 200% How much pressure affects thickness. 0% = no effect, 200% = very dramatic 100%
Smooth Drawing Apply curve smoothing On
Enable Hotkeys Allow global keyboard shortcuts On

Keyboard Shortcuts

HoverScribble supports customizable keyboard shortcuts. All shortcuts use Ctrl+Shift as a modifier to avoid conflicts with other applications.

Toggle HoverScribble Ctrl+Shift+P
Mouse Mode Ctrl+Shift+M
Pen Tool Ctrl+Shift+D
Highlighter Ctrl+Shift+H
Eraser Ctrl+Shift+E
Line Ctrl+Shift+L
Arrow Ctrl+Shift+A
Rectangle Ctrl+Shift+R
Ellipse Ctrl+Shift+O
Text Ctrl+Shift+T
Ruler Ctrl+Shift+U
Whiteboard Ctrl+Shift+W
Blackboard Ctrl+Shift+B
Fading Ink Ctrl+Shift+F
Clear Canvas Ctrl+Shift+C
Screenshot Ctrl+Shift+S
Undo Ctrl+Z
Mini Mode Ctrl+Shift+N
Minimize Ctrl+Shift+X

Shortcuts can be customized in Settings. All shortcuts are saved to your settings file.

Toolbar Customization

The toolbar can be fully customized to show only the tools you need.

Enabling/Disabling Tools

Open Settings and go to "Enabled Tools" to toggle individual tools on or off. Disabled tools will not appear in the toolbar.

Custom Colors

The toolbar shows 8 quick-access colors. You can customize these in Settings under "Default Colors". Click on any color swatch to change it.

Toolbar Position

Drag the toolbar by its edge to reposition it anywhere on screen. The position is saved between sessions.

Mini Mode: Press Ctrl+Shift+N to toggle a minimal toolbar with just essential tools.