Now in beta on iPhone · App Store soon

Your stack,
understood.

Stacky treats your supplements like the physical things they are: bottles that empty as you log, doses checked against published limits, pairs that help or cancel out. Everything it tells you is traceable to a source.

Join the beta on TestFlight
Free to start Sourced to EFSA & NIH No ads, no tracking SDKs
01 · Today

A shelf that empties as you do.

Every product on Today is drawn as its real container — bottle, jar, dropper, pouch — with a fill level that tracks what's actually left. Tick a dose and the day fills in. Skip one and it stays visibly missing. No streak theatre.

Grouped by time block. Morning, afternoon, evening — each with its own Mark all, one tap for the whole block.
A week you can read at a glance. Rings for each day; a gap is how an unlogged day announces itself.
Mood, asked at the right hour. The check-in opens at midday and never in a modal — a coerced 3/5 is worse than a missing day.
02 · Stack

Every bottle, tracked to the last day.

Your library knows what's running low before you do. Each product carries its dose, its schedule, and how many days are left at your pace — and the shelf sorts by what needs you first.

Add by scanning. Barcode first, label photo when there isn't one. The product fills itself in.
Make it yours. Pick the vessel, tint the body, colour the contents, print the label. It's the same object on Today, on Stack, on your Passport.
Low-stock nudges, not nagging. One quiet banner when something drops under a week — with a reorder link.
03 · Overview

An instrument panel, not a dashboard.

Four questions, always in the same place: what needs you, how much of this can you even see, what shape the stack is in, and what it costs. Day one and a fifteen-product stack get the same instruments — only the answers change.

Loud only when it's earned. Coral is reserved for a dose above a named published upper limit. Anything softer stays amber.
Coverage, stated plainly. “2 of 10 compared” means exactly that. Null is never quietly turned into zero.
Cost as a rate. €4.05 a day, €123+ a month — and which product is the expensive one.
04 · Explore

What we actually know.

A library of 200 substances, each graded A to D on the strength of the human research behind it — computed from study type, size and consistency, never opinion. 930 studies cited, every one a tap from PubMed.

How grades work is a page, not a secret. The rubric is public and the app can show you why a grade is what it is.
Stacks worth copying. Ours and members’, by goal. Save one, follow the person, borrow what works.
Most stacked. What people actually take, ranked — not what's trending on a feed.
MG
Magnesium Glycinate
Minerals · 128 people taking this
A
Strong evidenceConsistent results across randomised trials and meta-analyses
EU upper limit250 mgEFSA · supplemental, adults
US RDA310–420 mgNIH ODS · total intake, context only
META2021 · Journal of Clinical Sleep Medicine
The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial
RCT2017 · Nutrients
Magnesium supplementation and indicators of sleep quality in adults: a randomized controlled trial
Backed by 14 studies · How grading works →
Receipts

Every number has a source you can open.

Reference values come from EFSA and the NIH Office of Dietary Supplements, one row per figure, each with the document it came from. Interactions are quoted from named authorities or they aren't in the app — 45 today, none guessed. We would rather show you less than make it up.

05 · Passport

Your stack is the card.

One shareable artefact: the products you tick, drawn as your own vessels, on a material you've earned. Mood, adherence, notes and streaks are never on it — not as a setting, they simply aren't in the shared data. Products you've marked private start unticked. Cost is opt-in.

Share as an image, or copy as text for Reddit and group chats. Rename it by tapping the title.
No public web page. The card and the text are the whole share surface — a revocable link does not revoke a search cache.
Materials are earned by logging. Slate from day one; bronze at 7 days, silver at 30, gold at 90, obsidian at 365. Diamond comes with Premium.
STACKYAlex's Stack9 products · 41 substancesS
SlateFrom day one
STACKYAlex's Stack9 products · 41 substancesS
Bronze7 logged days
STACKYAlex's Stack9 products · 41 substancesS
Silver30 logged days
STACKYAlex's Stack9 products · 41 substancesS
Gold90 logged days
STACKYAlex's Stack9 products · 41 substancesS
Obsidian365 logged days
06 · Advisor

An advisor that reads your stack back.

Observational insights in plain language: doubled-up labels, timing clashes, well-matched pairs, a goal nothing covers. It flags what's worth reviewing and never plays doctor — no score, no verdict, no target doses. Then ask it anything about the stack it just read.

Launched from the orb in the tab bar — the one place AI lives, so the rest of the app can stay quiet.
The analysis is free for everyone. One question per analysis on the free plan; the full conversation, with history, is Premium.
It sees the stack, not you. Names, doses and forms go to the model. Never your name, email, birth year, sex or mood history — and private products are excluded.
Stacky Premium

Everything you log is already telling a story. Premium reads it back.

  • Synergy mapSee which of your pairs actually work together — and which cancel out. Every edge sourced.
  • Mood signalHow your stack moves your mood on supplement days — measured, not guessed.
  • The full conversationAsk the advisor as much as you like, with history. The analysis itself stays free.
  • Cost intel & extended routine historyWhat your routine really costs, and 90 days of adherence instead of 7.
  • The Diamond cardAurora ice for your Passport, worn immediately. The metals keep accruing underneath.
Save 50%
Yearly
€29.99
€2.50 / month · €19.99 first year
Monthly
€4.99
€2.99 / month for the first year
Get Stacky

Billed through the App Store in your local currency; the exact price is shown before you confirm. Renews automatically unless cancelled 24 hours before the period ends. Cancel in Settings → Apple ID → Subscriptions. Full terms.

Free: unlimited stack Free: dose ranges Free: the analysis Free: Passport & sharing Free: export & erase
07 · And everything else

The details that make it a daily habit.

Scan the label

Point the camera at a barcode and the product fills itself in. No barcode? Photograph the label and it's read for you.

Reminders that group up

One nudge per time block, not one per pill. Quiet hours respected. Mark the whole block from the notification.

Mood, in a tap

Five faces, asked after midday. Answer from the notification without opening the app.

Dose ranges, checked against the literature

Your daily amount of each substance, set against EFSA and NIH reference values — the RDA as context, the upper limit as the only line that classifies.

Magnesium · 200 mg supplementalUnder the EU upper limit

Yours to take with you

Export the whole ledger — stack, every intake with its timestamp, moods, the change log — as spreadsheets plus one JSON. Or erase the account, for real, in one tap.

Light and dark

Warm paper by day, near-black by night. The bottles are the same objects in both.

Six languages

English, Español, Português, Français, Deutsch, Italiano — every string, not just the menus.

Sign in your way

Email, Apple or Google. Hide My Email works normally. Health details are asked for separately, and encrypted.

08 · Questions

Straight answers.

Anything else — support@stacky-app.com is a real inbox, read by the person who builds the app.

When does Stacky launch?
The beta is live on iPhone right now — join it through TestFlight today. The App Store release follows; the waitlist gets you first in line, and the email you leave is used for that and nothing else.
Is Stacky medical advice?
No. Stacky is an organisational tool: it records what you choose to take and shows you information about it. It never prescribes doses, and the advisor is observational by design — it flags things worth reviewing with a professional. Talk to a doctor or pharmacist before starting, stopping or changing any supplement.
Where do the numbers come from?
Reference values are one row per figure from EFSA and the NIH Office of Dietary Supplements, each with its source document. Only a published upper limit classifies a dose; an RDA is total intake from food and supplements, so it's shown as context, never as a bound. Interactions are quoted from named public authorities — 45 today — and nothing is added on a guess.
How do evidence grades work?
Every substance is graded A to D on the strength of the human research behind it — study type, size and consistency, computed from the 930+ studies cited across the catalog. The grade is per substance, not per outcome, and the rubric is public inside the app under “How grades work”. About 63% of the catalog is grade A. That's real; we don't hide it.
What's free and what's Premium?
Free: an unlimited stack, Today, dose ranges, the AI analysis with one question per analysis, the Passport and sharing, export and erase. Premium adds the synergy map, mood signal, cost intel, 90 days of routine history, the full advisor conversation, and the Diamond card. €4.99 a month or €29.99 a year — €2.99 a month or €19.99 for your first year as an early adopter. Billed by Apple in your local currency, cancel in Settings any time.
Is my data private?
Your stack is private by default; sharing is always opt-in. There is no advertising or analytics SDK in the app and we do not sell data. Health details are encrypted at rest. You can export everything or permanently erase your account from inside the app. The Privacy Policy lists every provider that touches your data.
What about Android?
iPhone comes first. If you're on Android, join the waitlist and the Discord and say so — demand decides what we build next.

Built one honest day at a time.

Join the waitlist and be first in line for the App Store release. Or start today on TestFlight.

Or jump straight into the beta on TestFlight →