PlotRuler v0.1.2

What's new

Number format options — the readout can be shown as Auto, Plain, Scientific (m × 10ⁿ), Engineering, E notation, or SI prefixes (12.3 k). Switch with number keys 1-6 when focused, or from the tray menu → Number Format. The choice persists across restarts.
Log axes — after the second value on each axis, a Linear/Log choice appears. Both axes can be log or linear independently; a log axis fits the calibration in log space so it reads across orders of magnitude. Log scale is skipped automatically when an anchor value is zero or negative.
Much smaller executable — the build excludes unused Qt modules, dropping from ~257 MB to ~46 MB.
Overlay polish — bigger resize handles, larger and consistent instruction text near the bottom of the window, and the readout lines are cleaner.

Download PlotRuler.exe, run it, and use the tray icon (Win+Alt+P toggles the overlay, Ctrl+N starts a calibration). No Python install needed.

Linux: Wayland forbids the global screen coordinates the overlay's calibration model depends on, and X11 is being removed from modern GNOME/Ubuntu sessions. Cross-platform support is being worked on separately.