Comparison

Trajectory vs PepStack

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

Head to head
About

Trajectory

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Trajectory focuses on long-term direction instead of daily noise, so you can stay consistent without overreacting. TRACK YOUR WEIGHT EFFORTLESSLY • Log your weight in seconds • Supports kg and lbs • Full history STAY ON COURSE • Set a target weight and deadline • See your personal trajectory line • Know exactly where you should be today UNDERSTAND YOUR BODY • BMI tracking with instant feedback • 7-day trend to spot momentum • Progress toward your goal CLEAN & FOCUSED • No subscriptions. Free. • Beautiful chart that tells the whole story Trajectory doesn't judge. It doesn't nag. It just shows you the path, and whether you're on it.

About

PepStack

Features
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PepStack is a reconstitution and dosing-math calculator and protocol scheduler for peptide researchers. CALCULATE WITH CONFIDENCE • Exact BAC-water volume, concentration, syringe units, and doses-per-vial • Supports U-100 / U-50 / U-40 / U-30 insulin syringes • Step-by-step reconstitution guide PLAN YOUR PROTOCOL • Build a weekly schedule and sync dose reminders • Log doses, track streaks, rotate injection sites • Reference library of common research peptides STAY ORGANIZED • Vial inventory with expiry and low-stock alerts • Optional Apple Health sync for weight & body-fat trends • Wellness journal and progress insights PepStack is an educational calculator. It is not medical advice and does not sell or supply any substance. Always consult a qualified professional. PepStack Pro is an auto-renewable subscription (monthly or annual). Payment is charged to your Apple ID; it auto-renews unless canceled at least 24 hours before the period ends. Manage or cancel in Settings. Pro unlocks unlimited protocols, dose logging, AI insights, and PDF export. Terms of Use (EULA): https://pepstack.co/terms Privacy Policy: https://pepstack.co/privacy

Screenshots

PepStack4 screens

Verdict

The call

The clearest difference is in-app purchases: Trajectory at none against PepStack's 2. PepStack's advantage is device support. On price and iOS requirement there is nothing between them.

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

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

Both are free to download. PepStack sells 2 in-app purchases, starting at $4.99 per month. Trajectory asks for nothing beyond the download.

Scorecard2 real differences Ā· 3 level
Trajectory versus PepStack: the parameters behind the verdict, then further details
ParameterTrajectoryPepStack
PriceFreeFree
Ads—No
In-app purchasesNo — betterYes
Devices—iPhone, Apple Watch — better
Requires iOS18.517.0 — better
Further details — not scored
Size2 MB9 MB
Age rating17+4+
DeveloperMathieu BonteDaniel Son, LLC

In-app purchases

None

Trajectory

No in-app purchases

2 purchases

PepStack

Subscriptions2
  • PepStack Pro Monthly$4.991 Month
  • PepStack Pro Annual7 Days trial$29.991 Year

Questions

Is Trajectory free?
Trajectory is free to download, with no in-app purchases.
Is PepStack free?
PepStack is free to download, with in-app purchases available.

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