PlainWater - Water Safety

Water is the most basic thing every human — and every animal — needs after oxygen. Yet the expertise to find, test, and make water safe to drink is normally locked behind labs, NGOs, and public-health departments. PlainWater puts it directly in your pocket, offline — because the roughly 2 billion people who need it most often have no signal and no money for a lab test, and even in wealthy countries, boil-water advisories and disasters knock out safe water routinely. 82 features across 8 modules, entirely on-device: • PURIFICATION — boiling (altitude-adjusted), bleach/chlorine dosing calculator, purification tablets, SODIS, filtration, distillation, DIY builds (biosand, ceramic pot), and more — every method with exact, sourced numbers, not rules of thumb. • ILLNESS & REHYDRATION — symptom guides for cholera, giardia, dysentery, typhoid; a red-flag triage that tells you when to seek help now; a home ORS (oral rehydration) calculator using the WHO-standard ratio; age-specific guidance for infants, children, elderly, and immunocompromised people. • EVERYDAY HEALTH — how much water you actually need day to day, overhydration risk, mild dehydration's effect on mood and focus, pet and animal water hazards (blue-green algae is often fatal to dogs within hours), recreational swimming safety. • TEST KIT & METER INTERPRETATION — turn a strip, meter, or kit color into a decision. • SOURCING & STORAGE — emergency water sourcing, storage best practices, well and rainwater safety, a water-needs calculator, a disaster-kit rotation reminder. • REGION & DISASTER GUIDANCE — boil-water-advisory checklists, an interactive "is my tap water safe" decision tree, flood/earthquake/hurricane/wildfire-specific guidance (free on principle — you need this most exactly when you can least afford to pay for it). • ACCESSIBILITY — full-text search, audio read-aloud, icon-first mode for low-literacy users, screen-reader support, color-reference swatches, offline water-point mapping with saved pins, PDF export for a physical go-bag backup. Every guidance claim is cited to a free, public, authoritative source — WHO, CDC, EPA, USGS, Ready.gov/FEMA, the American Red Cross, UNICEF/WHO's Joint Monitoring Programme, and CAWST. Tap any citation to read the source yourself. No paywalled journals, no commercial or vendor sources — ever. 100% ON-DEVICE, ALWAYS: • No accounts. No servers, ever — not now, not as a future paid tier. • Optional sync of your own data (a saved plan, reminders) uses only your device's own backup — never a company-run server. • No ads. No tracking. A generous free tier covers every life-critical feature, permanently — illness recognition, core purification methods, emergency sourcing, and all disaster-triggered guidance. Deeper, enthusiast, and homeowner-convenience content unlocks with a one-time "PlainWater Pro" purchase, smaller à la carte packs, or — if you'd rather not pay all at once — a monthly or yearly subscription that unlocks exactly the same content. Both options are handled entirely by Google Play; PlainWater itself runs no server of any kind, for either payment path. PlainWater provides educational guidance, not diagnosis or water-testing certification. When in doubt, it always tells you to treat or boil — and to seek professional medical care for symptoms of illness.

Updated for Android 16 and the latest Google Play requirements. Stability and performance improvements.