Not for commercial use, but many universities provide free licenses. A trial version exists with a limit of ~10 data points per session.

For noisy, dashed, or overlapping curves, manual mode gives you full control. You can zoom into pixel-level precision.

The most critical part of digitizing is telling the software where the axes are. GetData allows you to zoom in on the axis ticks with a magnifying lens that offers sub-pixel precision. You can precisely place your cursor on the gridlines, ensuring that your X=0 and Y=0 are mathematically accurate.