# Booked (Previously PTO) vs Peptide Library

The clearest difference is update cadence: Peptide Library at every 5 days against Booked (Previously PTO)'s every 2 months. Booked (Previously PTO)'s advantage is device support (3 vs 1) and iOS requirement (15.0 vs 18.0). On price, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Booked (Previously PTO) ships an update every 2 months, Peptide Library every 5 days. The most recent releases landed on October 24, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Booked (Previously PTO) | Peptide Library |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 6.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 days** |
| Monetization | Free | — |
| Size | 5 MB | 16 MB |
| Requires iOS | **15.0** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [CountryNet Software](https://appshunter.io/developer/1089092090) | [Jay Park](https://appshunter.io/developer/6808156571) |

## What reviewers say

### Booked (Previously PTO)

[App page](https://appshunter.io/ios/app/booked-previously-pto/id1089092091)

This app allows users to book, change, or access scheduled school events like in-person meetings, online sessions, or phone calls. It serves as a mobile extension of a school's web-based booking system. Access is granted through an active school subscription.

**Highlights:** Book scheduled school events, Modify existing bookings, Access bookings on the go, Supports in-person, online, and phone events, Mobile extension of web platform

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

**In-app purchases:** none


### Peptide Library

[App page](https://appshunter.io/ios/app/peptide-library/id6808156569)

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

**In-app purchases:** none


## Frequently asked questions

### Is Booked (Previously PTO) free?

Booked (Previously PTO) is free to download, with no in-app purchases.

### Is Peptide Library free?

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

### Do Booked (Previously PTO) or Peptide Library have ads?

Neither Booked (Previously PTO) nor Peptide Library shows ads.

### Which is updated more often, Booked (Previously PTO) or Peptide Library?

Booked (Previously PTO) ships an update every 2 months, and Peptide Library every 5 days. Most recently, Booked (Previously PTO) was updated on October 24, 2026 and Peptide Library 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.*