Take a picture of a thin-layer chromatography plate, or open a PNG, a JPEG or a PDF from a scanner. Fit four corners to the plate and it is straightened, however it was photographed.
The origin, the front and the spots are found for you, with the colour each spot shows. Move any of them, name what each spot is, and take the plate away as a figure or a table of Rf values.
Straighten a picture of a thin-layer chromatography plate, mark its spots and read every Rf value, then weigh its eluent on a solvent scale. The tool needs JavaScript, because the picture is read in your browser.