Ruler is a simple onscreen ruler. It runs as a packaged app, separate from any browser tab. Get the source at https://github.com/astromme/Ruler Features: * Support for pixels, inches, and centimeters * Both Horizontal and Vertical rulers * Move the ruler with your arrow keys (+ shift for 10px changes) * resize the ruler with your arrow keys + alt (+ shift for 100px changes) * Calibrate the ruler with your screen size * Exists separately from any browser tab * Easily resizable * Settings are remembered across launches * Always on top mode