Solves sync to the server for this address. Leave blank to keep them in this browser only.
A short exercise: mark only the cells you're sure of on single lines.
Helps tune the difficulty model to your inference style.
Clears this browser's saved solve history and theme, then reloads. Your email
and any solves still waiting to upload are kept, and data already saved on
the server is not affected.
Calibrate
Mark a cell only if the clues prove it —
some probes are single lines, some are small boards. If you are not certain,
you must leave the cell blank; a hopeful mark spoils the measurement.
Leaving a probe completely blank is often the right answer. Pick a paint color, then tap or drag to paint it; tapping a cell
already in that color clears it. Space or the swatch flips the color.