Yarrow: Offline Herbal Guide

Power Prepper LLC

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About this app

Yarrow is an educational reference. It is not a medical device and does not diagnose, treat, cure, or prevent any medical condition. Always consult a healthcare professional for medical advice.

The herbal reference library that works offline. Centuries of historical herbals, modern NIH safety summaries, and an AI librarian that cites its sources — all on your device after a one-time download. No account. No ads. No tracking. No internet needed.

100 IN-DEPTH HERB MONOGRAPHS
Every monograph tells the whole story: what the plant was traditionally used for, what modern evidence actually says (drawn from NIH/NCCIH summaries — often "limited" or "insufficient," and we say so), and the safety picture — side effects, contraindications, and documented drug interactions. Honesty is the brand.

56 NIH / NCCIH HERB FACT SHEETS
The "Herbs at a Glance" collection from the National Center for Complementary and Integrative Health — the same evidence and safety information in NIH's own HerbList — searchable offline.

HISTORICAL HERBALS, HONESTLY LABELED
Read King's American Dispensatory (1905), Culpeper's Complete Herbal (1880 edition) and other classic texts as they were written. Every historical source carries a clear era label — these are historical documents that show how plants were once understood, not modern medical guidance.

HERB–DRUG INTERACTION CHECKER
Look up documented interactions between herbs and medications, surfaced proactively on every plant page. Yarrow tells you what is documented and what is unknown — and unknown does not mean safe. Interaction questions always end the same way: ask your pharmacist or doctor.

DANGEROUS-PLANTS GUIDE
A curated hard-warning guide to plants the historical literature praised and modern science flags — ephedra, comfrey taken internally, pennyroyal oil and more. Red cards outrank everything else in the app.

TRADITIONAL PREPARATIONS GUIDE
How infusions, decoctions, tinctures, salves and poultices were traditionally made — presented as heritage knowledge and craft, with safety notes throughout.

HARVEST CALENDAR WITH LOOKALIKE WARNINGS
When plants are traditionally gathered — with prominent warnings about toxic lookalikes for the species that have them.

PLANT & MUSHROOM PHOTO ID
Point the camera for an on-device identification starting point. ID is never a green light: results come with confidence caveats and lookalike cautions, and nothing in Yarrow tells you something is safe to consume.

AI LIBRARIAN WITH CITATIONS
Ask in plain language and get an answer built only from the included texts, with tap-able citations to the exact sources — a reference librarian for this library, not a medical adviser. It reminds you to consult a professional, refuses unsafe requests, and every answer can be flagged for review.

100% OFFLINE · ZERO DATA COLLECTION
Your questions, photos and bookmarks never leave your phone. No cloud, no login, no analytics. The internet is used for the one-time library download, and for any source link you choose to open.

YOU PICK HOW YOU PAY
Unlock everything forever with a single $19.99 payment — no renewal, no check-ins, offline for life. Or subscribe yearly for $9.99 if you'd rather start smaller; cancel anytime in Google Play. Both plans unlock exactly the same library. Never a monthly fee, never an account.

Yarrow is for learning what plants meant to the people who came before us, and what modern evidence says today. For any health concern, see a qualified healthcare professional.

What’s new

First release.

100 herb monographs — what each plant was traditionally used for, what the evidence actually says, and the safety picture including documented drug interactions. 56 NIH/NCCIH fact sheets. Historical herbals such as King's American Dispensatory (1905) and Culpeper (1880), each labelled by era.

Search and AI answers cite their sources. Everything runs on your device after a one-time download.

Educational reference — not medical advice.