Comparison

StackFlow vs StackDay

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

StackFlow

This app helps you manage complex supplement routines by scanning labels, providing AI-driven timing suggestions based on ingredient interactions, and tracking your body's response. It visualizes synergy and spacing for optimal intake.

Highlights
  • AI-powered supplement timing
  • Supplement label scanning
  • Ingredient-level intelligence
  • Synergy and spacing visualization
  • Daily routine tracking
  • Body response logging
  • Daily insights feed
Features
Read full description

Taking multiple supplements every day? The hard part is not remembering them — it is knowing what goes together, what needs spacing, and when each one works best. StackFlow turns supplement chaos into a clear, executable daily system. BUILT ON 200K+ REAL SUPPLEMENT PRODUCTS Search or scan real products with real ingredients, real serving sizes, and real label facts — not a generic vitamin list. INGREDIENT-LEVEL INTELLIGENCE StackFlow maps each product to its actual ingredients, so you understand what you are really taking — not just the brand name on the bottle. SCAN A LABEL, ADD IN SECONDS Point your camera at any supplement label. StackFlow reads the product, maps the ingredients, and places it into your routine. AI TIMING PLANS THAT EXPLAIN WHY Get timing suggestions based on ingredient interactions, absorption rules, and your current stack. Every recommendation shows the reasoning behind it. SYNERGY AND SPACING, MADE VISIBLE See which supplements work better together, which ones need to be spaced apart, and why your routine is organized the way it is. YOUR DAILY COMMAND CENTER Open StackFlow each morning. See exactly what to take now, check off each time slot, and keep your routine moving without guesswork. TRACK HOW YOUR BODY RESPONDS Log energy, sleep, digestion, and other signals. Over time, connect your routine to what you actually notice. DAILY INSIGHTS FEED (PRO) Receive a curated daily digest based on your stack, check-ins, and patterns — not a generic health tip, but intelligence about your specific routine. StackFlow is built for people who take supplement routines seriously. It is not medical advice, diagnosis, or treatment. Privacy Policy: https://www.stackflow.life/privacy.html Terms of Use (EULA): https://www.stackflow.life/terms.html

About

StackDay

This app helps you consistently take your vitamins and supplements. Log doses, build streaks, and view your adherence over time. It offers smart reminders and pre-loaded supplement information to make tracking easy.

Highlights
  • Daily checklist for all supplements
  • 50+ pre-loaded supplements
  • Streak and adherence statistics
  • Customizable smart reminders
  • Local data storage for privacy
  • Home screen widget (Pro)
Features
Read full description

StackDay is the supplement and peptide tracker that finally makes you consistent — check off doses in one tap, watch your streak grow, and see which stacks actually work. NEW: PEPTIDES + PROTOCOLS A dedicated Peptides tab for BPC-157, TB-500, semaglutide, retatrutide, and every peptide in between. • Vial tracking with a 28-day reconstitution countdown • Titration schedules that auto-step your dose week by week for GLP-1s • Active-level curves (Pro) — see estimated compound levels between doses so you know when the next one is really due RECONSTITUTION CALCULATOR Enter your vial strength and BAC water; get exact U-100 syringe units instantly. Reverse mode lets you dial a target dose and see the water to add — no more scribbling on the back of a bottle. INJECTION SITE ROTATION A tappable body map covering all 8 subQ sites. Auto-suggests the most-rested spot every time you log a dose, so you never accidentally double up. DAILY CHECKLIST Your entire stack in one screen, split by morning, meal, afternoon, pre-workout, evening, and bedtime. Tap to check off each supplement. Satisfying haptics every time. 1,000+ SUPPLEMENT LIBRARY Vitamins, minerals, adaptogens, nootropics, mushrooms, and performance compounds — all pre-loaded with common dosages and units. Add your full stack in 30 seconds. Scan any label with your camera (Pro). STREAKS, QUESTS, AND BADGES • 24 illustrated achievement badges spanning streaks, logging milestones, peptides, and exploration • 3 weekly quests that rotate on a fresh cycle every week • Streak Freezes bank automatically at milestones and protect a missed day — because life happens INTERACTIVE WIDGETS • Medium Home Screen widget with tap-to-check-off buttons — mark doses without opening the app • Small widget and Lock Screen widgets for at-a-glance progress • Peptide widget showing your next dose and vial countdown • Mark doses taken right from notifications INTERACTION AWARENESS 16 built-in interaction checks (calcium and iron, coffee and ashwagandha, and more). Timing suggestions space competing supplements hours apart so absorption doesn't fight itself. PROGRESS THAT MEANS SOMETHING • 30-day adherence per supplement — see your true best performers • Monthly heatmap calendar • Wellness correlation (Pro) — spot which supplements actually move your mood, energy, sleep, and focus • Apple Health integration for sleep, steps, and workouts STACKDAY PRO • Unlimited history and full per-supplement stats • Active-level curves for peptides • Custom reminder times for every one of the 8 slots • Label scanner and AI Supplement Advisor • Wellness correlation insights and weekly recaps Free tier includes full daily tracking, 7-day history, slot reminders, and the reconstitution calculator. NOW IN 6 LANGUAGES English, German, Spanish, French, Portuguese, and Japanese — with more on the way. PRIVATE BY DESIGN Your data stays on your iPhone. No account required. Everything is stored locally. Built for anyone who spends money on supplements and peptides but never sees the payoff because they can't stay consistent. Every dose logged. Every streak counted. Every stack proven. Privacy Policy: https://foggy-labs.github.io/privacy/stackday Terms of Use: https://foggy-labs.github.io/terms Support: https://foggy-labs.github.io/support

Screenshots

StackFlow4 screens
StackDay4 screens

Verdict

The call

The clearest difference is ads: StackFlow at none against StackDay's shown. StackDay's advantage is update cadence (every 3 days vs every 2 weeks) and ratings volume (5 vs 1). On price, rating, review sentiment and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. StackFlow sells 2 in-app purchases, starting at $4.99 per month and StackDay sells 8 in-app purchases, starting at $0.99 per 7 days. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for StackFlow against 5.0 for StackDay. That said, the two scores are not equally well evidenced: StackDay has 5 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

StackFlow ships an update every 2 weeks, StackDay every 3 days. The most recent releases landed on July 11, 2026 and September 6, 2026 respectively.

Scorecard3 real differences · 7 level
StackFlow versus StackDay: the parameters behind the verdict, then further details
ParameterStackFlowStackDay
PriceFreeFree
Rating5.0 (1 ratings)5.0 (5 ratings)
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings15 — better
Update frequencyEvery 2 weeksEvery 3 days — better
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFreemium
DevicesiPhone, iPad — betteriPhone
Requires iOS17.617.0 — better
Further details — not scored
Size5 MB20 MB
Age rating4+12+
Developer航东 郭Fog Hill, LLC

Customer experience

StackFlow

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

StackDay

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

2 purchases

StackFlow

Subscriptions2
  • StackFlow Pro Monthly1 Month trial$4.991 Month
  • StackFlow Pro Annual$29.991 Year
8 purchases

StackDay

Subscriptions8
  • Pro Weekly Discount3 Days trial$0.997 Days
  • Pro Weekly3 Days trial$1.997 Days
  • Pro Monthly Discount$3.991 Month
Show 5 more
  • StackDay Pro Monthly$4.991 Month
  • StackDay Pro Monthly Subscription3 Days trial$4.991 Month
  • Pro Annual Discount$19.991 Year
  • StackDay Pro Annual Subscription3 Days trial$24.991 Year
  • StackDay Pro Annual7 Days trial$49.991 Year

Questions

Is StackFlow free?
StackFlow is free to download, with in-app purchases available.
Is StackDay free?
StackDay is free to download, with in-app purchases available.
Which has better reviews, StackFlow or StackDay?
StackFlow and StackDay are both rated 5.0 out of 5 on the App Store, from 1 and 5 ratings respectively.
Do StackFlow or StackDay have ads?
StackDay shows ads; StackFlow does not.
Which is updated more often, StackFlow or StackDay?
StackFlow ships an update every 2 weeks, and StackDay every 3 days. Most recently, StackFlow was updated on July 11, 2026 and StackDay on September 6, 2026.

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