Comparison

Stackr vs 21 Pilates NYC

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

Head to head
About

Stackr

This app simplifies tracking peptide and GLP-1 doses, including supplies like vials and pens. It offers smart reminders, home screen widgets, and visual charts of estimated active levels based on half-life. Designed for users managing peptide protocols, it keeps your dosing information organized and accessible.

Highlights
  • Log peptide and GLP-1 doses
  • Track vials, pens, and other supplies
  • Smart reminders for next doses
  • Home screen widgets
  • Estimated active level charts
  • Multi-peptide stack tracking
  • Reference pages for common compounds
Features
Read full description

Stackr is the all-in-one tracker for your peptide and GLP-1 protocol. Every dose, vial and meal in one place, with the math done for you. KEY FEATURES • Dose tracking and reminders Log a dose in seconds from your Home screen. Run daily, weekly, every-few-days or specific-day schedules, and several protocols at once. Reminders make sure you never miss a dose, and Home Screen widgets show what's next. • Dose calculator Enter your vial strength, water and dose, and see exactly how many units to draw on a U-100 or U-40 syringe. Works in mcg, mg, IU and units. • Supplies and vials Track vials, pens and other supplies. Stackr counts down what's left every time you log and warns you before you run out. • Progress Keep your weight, progress photos and dose history together, with a calendar of taken and missed doses and estimated active levels from your logs. • Food and calories Snap a meal, scan a barcode, search a food or just say what you ate. Stackr tracks calories and protein against your daily plan. • Stackr Coach Ask the AI coach questions about your routine and your meals, any time. • Learn Reference pages for semaglutide, tirzepatide, retatrutide, BPC-157, TB-500, GHK-Cu and 100+ more, with research status and sources. WHY STACKR • Built for GLP-1s and peptides, from one weekly shot to a full stack • Pounds or kilograms, mcg or mg, U-100 or U-40 • Syncs across your devices when you sign in • Message the team directly from Settings Stackr is a personal tracking and educational app. It does not give medical advice, prescribe treatments or tell you which peptide, dose or schedule is right for you. Always talk to a qualified healthcare professional. Active levels and photo-based nutrition values are estimates. SUBSCRIPTION Stackr is free to download. Full access requires a paid Stackr+ subscription. Payment is charged to your Apple Account at confirmation of purchase. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. Manage or cancel your subscription in your Apple Account settings. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://getstackr.app/privacy

About

21 Pilates NYC

Features
Read full description

Download the 21 Pilates NYC App today to plan and schedule your classes! From this mobile App, you can view class schedules and sign up for classes as well as view the studio’s location. Optimize your time and maximize the convenience of signing up for classes from your device! Download this App today!

Screenshots

Stackr4 screens
21 Pilates NYC3 screens

Verdict

The call

The clearest difference is in-app purchases: 21 Pilates NYC at none against Stackr's 7. Stackr's advantage is update cadence (weekly vs every 2 weeks). On price, ads, device support and iOS requirement 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. Stackr sells 7 in-app purchases, starting at $7.99 per 7 days. 21 Pilates NYC asks for nothing beyond the download.

UpkeepUpdate frequency

Stackr ships an update weekly, 21 Pilates NYC every 2 weeks. The most recent releases landed on October 29, 2026 and October 12, 2026 respectively.

Scorecard2 real differences · 8 level
Stackr versus 21 Pilates NYC: the parameters behind the verdict, then further details
ParameterStackr21 Pilates NYC
PriceFreeFree
Rating4.4 (198 ratings) — better—
Positive reviews68.8% of reviews—
Number of ratings198 — better—
Update frequencyWeekly — betterEvery 2 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhoneiPhone, iPad — better
Requires iOS17.016.0 — better
Further details — not scored
Size88 MB192 MB
Age rating12+4+
DeveloperStackr Holdings LLC21 PilatesNYC LLC

In-app purchases

7 purchases

Stackr

Subscriptions7
  • Stackr+ Weekly$7.997 Days
  • Monthly$12.991 Month
  • Stackr+ Yearly$29.991 Year
Show 4 more
  • Stackr+ Yearly$49.991 Year
  • Stackr+ Yearly3 Days trial$49.991 Year
  • Stackr+ Yearly$59.991 Year
  • Yearly3 Days trial$69.991 Year
None

21 Pilates NYC

No in-app purchases

Questions

Is Stackr free?
Stackr is free to download, with in-app purchases available.
Is 21 Pilates NYC free?
21 Pilates NYC is free to download, with no in-app purchases.
Do Stackr or 21 Pilates NYC have ads?
Neither Stackr nor 21 Pilates NYC shows ads.
Which is updated more often, Stackr or 21 Pilates NYC?
Stackr ships an update weekly, and 21 Pilates NYC every 2 weeks. Most recently, Stackr was updated on October 29, 2026 and 21 Pilates NYC on October 12, 2026.

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