G Dev Toolbox

Measure, inspect & pick colors

Only for Mac

Free

Mac

G Dev Toolbox is a lightweight menu bar app that puts five precision overlay tools at your fingertips. Whether you're inspecting a design, measuring spacing, or sampling a color, everything happens directly on your screen — no screenshots, no switching apps. TOOLS Crosshair — A full-screen crosshair that locks to your cursor. Useful for aligning elements across windows or checking visual symmetry at a glance. Loupe — A magnifier that follows your cursor and shows the pixels under it at up to 8× zoom. Zoom in and out using the arrow keys. Perfect for checking sub-pixel rendering and retina assets. Ruler — Click to set a start point, then move your cursor to measure the distance in points, pixels, or CSS rem. Tap Escape to reset and start a new measurement. Angle — Click once to set the vertex, click again to fix the first arm, then move your cursor to read the angle in real time. Useful for measuring rotations, gradients, and perspective. Color Picker — Samples the colour under your cursor and displays its hex value. Press ⌘⇧C to copy the hex code to your clipboard instantly. HOW IT WORKS Click the menu bar icon to choose a tool. The overlay appears immediately and follows your cursor across every display. Press Escape at any time to dismiss the overlay. All tools work across multiple monitors. The Loupe and Color Picker use ScreenCaptureKit to read pixel data directly — nothing is saved to disk. PERMISSIONS G Dev Toolbox requires Accessibility access to track your cursor globally. Screen Recording permission is needed for the Loupe and Color Picker. Both are requested on first launch and can be revoked at any time in System Settings. PRIVACY No analytics. No data collection. No network requests. Everything runs entirely on your Mac.

Ratings & Reviews

  • This app has not received enough ratings or reviews to display an overview.

This update fixes a Screen Recording permission prompt that could appear twice and get stuck when first using the Loupe or Color Picker. Enabling access is now a single, smooth step.

Version 1.0.1

The developer, Gabriel Castillo, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary based, for example, on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Provider
    • Gabriel Castillo
    Size
    • 1 MB
    Category
    • Developer Tools
    Compatibility
    Requires macOS 14.2 or later.
    • Mac
      Requires macOS 14.2 or later.
    Languages
    • English
    Age Rating
    4+
    Copyright
    • © 2026 Gabriel Castillo
  • Privacy Policy

    • More by Gabriel Castillo