Washday Lab is an offline laundry-knowledge game. Pick a garment, then make one choice at each of four steps - wash method, stain pre-treatment, washer settings, drying. Every choice comes with an explanation of its effect and an illustration: shrinking, felting, stiffening, fading, pilling, static, clumped down.

19 garments, 10 fabrics, 11 stains, 4 steps. Every verdict comes with its source: 43 entries, listed with URL and date of retrieval.

Each garment carries a care label - wash tub, bleach triangle, drying squares, iron, and the bars for gentler settings. Tap a symbol for its meaning and source, or use "Locate label" to scroll to it and highlight it.

After step four, the result screen shows the run score, the maximum and the star rating, the steps that went wrong with their verdicts, reasons, sources and better options, plus cleanliness and garment-health measures.

"Diagnose" starts from what you can see on the fabric - pilling, greying or yellowing, towels that no longer absorb, flat down, a smell that survives the wash, lint attraction, shrinkage, faded denim - identifies the cause, and gives a fix you can do at home with a before/after view.

The wardrobe groups all 19 garments by type and filters by type, stain and fabric. Cards show a preview, the fabric, the stains and your best score. Your last ten runs can be searched and replayed.

The interface is available in Simplified Chinese, English and Japanese, switchable inside the app. Four text sizes and three interface scales.

Fully offline: no account, no analytics or advertising SDK, no in-app purchases, and the release build requests no permissions. The save is one JSON file on your own device (settings plus the last ten runs) and is removed with the app. The app is not on the App Store yet, so this page offers no store link and no installer.