An Android app for serious cultivators. AI-generated grow plans, photo-based diagnosis, environment analysis from your AC Infinity controller, and smart reminders that never miss a day. Runs entirely on your device.
Grow Master is what you reach for instead of a spiral notebook, a half-forgotten spreadsheet, and a Reddit tab open in the background. It tracks your grow, reminds you what to do, analyzes your environment data, and gives you a master cultivator to text when something looks off.
It's built for indoor, outdoor, and greenhouse growers running autos or photos, in coco or soil or living soil, with hand-watering or autopot or DWC. The AI knows your exact setup because you told it once.
The surface area is intentionally small. Every feature exists because it moves the grow forward.
Six pages of questions about your cultivar, setup, medium, feed, and IPM. Claude researches each strain, synthesizes it all, and builds a grow file with phase targets, daily tasks, and a supply list. One tap to import.
Global chat for general questions. Grow-specific chat with full context: strains, phase, targets, last seven days of environment data, recent journal entries. Send a photo, get a diagnosis. If action is warranted, it offers a one-tap task to add.
Import daily CSVs via the Android share sheet. The app scores each day against phase targets with a weighted 0–100. Dual analysis runs two AI passes — last 24 hours and the rolling seven days — so a recent problem isn't averaged away.
Daily task batches by grow, weekly Sunday digest, critical-task flags, per-task time overrides, and shade-action snoozing (30 min / 1 hr / 3 hr / Tomorrow / Done) without opening the app. Notifications survive reboots.
Every active grow gets a card. Day count, days left, supplies to buy, tasks done. The instrument strip shows your current-phase targets — temp, RH, VPD, DLI — in the same uppercase mono the app uses everywhere, because numbers belong in monospace.
Tap the strip to see readings; tap a card for the full detail view with tasks, supplies, journal, and environment tabs.
Cannabis is still federally illegal in the U.S. Growers have legitimate reasons to care where their data sleeps at night. Grow Master is built so that the answer is simple: it sleeps on your phone.
"No server owned or operated by this app will ever see a single row of your data — because there is no server."
No account. No sign-in. No telemetry. No analytics. No crash reporting. No ad SDKs. The only network traffic the app makes is direct HTTPS to Anthropic, authenticated with your own API key, for the AI features you explicitly invoke.
Grows, tasks, journal, photos, API key, chat history — all of it stored on the device. Uninstall the app and it's gone.
You create the key in Anthropic's console, paste it in, set your own spending cap. Revoke it and the app makes zero further API calls.
API submissions are not used to train models, are retained for seven days, then deleted. ZDR available for enterprise. Verified April 2026.
If you want the app with zero network traffic of any kind, don't enter an API key. Task tracking, notifications, journal, environment charts, and grow file import/export all work fully offline.
Grow Master isn't on the Play Store. Download the latest APK from GitHub Releases and sideload it. You'll need to allow installs from "unknown sources" once.
Sign up at console.anthropic.com, add $5 of credit, generate an API key named grow-master.
In Settings → Claude API, paste the key and tap Verify. A minimal test call confirms it works. Then open the wizard and build your first grow.
There's no subscription, no pro tier, no paywalled features. You pay Anthropic for the AI tokens you actually use — nothing more.
Set a spending cap in the Anthropic console. The app's Settings → API usage tab breaks down your spending by feature so you always know exactly where your tokens go.