# PepSync vs ProStack

The clearest difference is in-app purchases: ProStack at none against PepSync's 1. ProStack also leads on update cadence (every 5 days vs every 3 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. PepSync sells 1 one-off in-app purchase. ProStack asks for nothing beyond the download.

PepSync ships an update every 3 weeks, ProStack every 5 days. The most recent releases landed on October 17, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | PepSync | ProStack |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (3 ratings)](https://appshunter.io/ios/app/prostack-peptide-tracker/id6789934657/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 5 days** |
| Monetization | — | Free |
| Size | 39 MB | 65 MB |
| Requires iOS | 16.4 | 16.4 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 17+ | 17+ |
| Developer | [Rapid Sync IT LLC](https://appshunter.io/developer/1887127351) | [JESSIE GRACE CHRISTIE](https://appshunter.io/developer/6789934659) |

## What reviewers say

### PepSync

[App page](https://appshunter.io/ios/app/pepsync-peptide-calculator/id6762025755)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock PepSync | $19.99 | one-time |


### ProStack

[App page](https://appshunter.io/ios/app/prostack-peptide-tracker/id6789934657)

Effortlessly calculate peptide dosages and track your cycles with instant syringe unit calculations. Log your progress, set reminders, and access a reference library for safe and effective use.

**Highlights:** Instant syringe unit calculation, Cycle tracking with calendar view, Dose reminders with auto-pause, Progress tracking (body composition, photos), Peptide reference library, Nasal spray calculator

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is PepSync free?

PepSync is free to download, with in-app purchases available.

### Is ProStack free?

ProStack is free to download, with no in-app purchases.

### Do PepSync or ProStack have ads?

Neither PepSync nor ProStack shows ads.

### Which is updated more often, PepSync or ProStack?

PepSync ships an update every 3 weeks, and ProStack every 5 days. Most recently, PepSync was updated on October 17, 2026 and ProStack on October 14, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*