# O2gO2 vs EMS Platoon Shift Calendar

The clearest difference is rating: EMS Platoon Shift Calendar at 4.2 against O2gO2's 3.0. EMS Platoon Shift Calendar also leads on in-app purchases (none vs 1) and update cadence (every 2 months vs every 28 months). O2gO2's advantage is ads (none vs shown) and iOS requirement (12.0 vs 16.0). On price and device support there is nothing between them.

Both are free to download. O2gO2 sells 1 in-app purchase, starting at $2.99 per year. EMS Platoon Shift Calendar asks for nothing beyond the download.

EMS Platoon Shift Calendar holds the better App Store score, 4.2 against 3.0. That said, the two scores are not equally well evidenced: EMS Platoon Shift Calendar has 25 ratings behind it against 2, so its average is the more settled of the two.

O2gO2 ships an update every 28 months, EMS Platoon Shift Calendar every 2 months. The most recent releases landed on October 19, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | O2gO2 | EMS Platoon Shift Calendar |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (2 ratings)](https://appshunter.io/ios/app/o2go2/id895990670/reviews) | **[4.2 (25 ratings)](https://appshunter.io/ios/app/ems-platoon-shift-calendar/id1175060031/reviews)** |
| Number of ratings | 2 | **25** |
| Positive reviews | — | 45.5% of reviews |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 28 months | **Every 2 months** |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 2 MB | 28 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Aeronautical Data Systems Inc.](https://appshunter.io/developer/552304929) | [Lato Productions, LLC](https://appshunter.io/developer/1175060030) |

## What reviewers say

### O2gO2

[App page](https://appshunter.io/ios/app/o2go2/id895990670)

This utility app converts oxygen cylinder pressure into remaining time, helping users manage their compressed gas resources. It provides visual indicators and calculates duration based on tank size, current pressure, and flow rate.

**Highlights:** Converts PSI to time remaining, Calculates duration based on tank size, pressure, and flow rate, Visual multicolored strip indicates oxygen level, Yellow and red indicators for low oxygen, Automatic reset for pressure input, Assumes consistent tank size

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| O2 Go2 Yearly Subscription | $2.99 | per year |


### EMS Platoon Shift Calendar

[App page](https://appshunter.io/ios/app/ems-platoon-shift-calendar/id1175060031)

This app helps emergency medical services personnel manage their platoon schedules. It allows users to select their platoon, view days off, and track overtime pay. It also includes a list of local hospitals and a 10-minute rule check.

**Highlights:** Platoon scheduling, Days off display, Mutual and off day tracking, Overtime pay calculation, Hospital directory, 10-minute rule check

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is O2gO2 free?

O2gO2 is free to download, with in-app purchases available.

### Is EMS Platoon Shift Calendar free?

EMS Platoon Shift Calendar is free to download, with no in-app purchases.

### Which has better reviews, O2gO2 or EMS Platoon Shift Calendar?

EMS Platoon Shift Calendar is rated higher. O2gO2 averages 3.0 out of 5 from 2 ratings, while EMS Platoon Shift Calendar averages 4.2 from 25 ratings.

### Do O2gO2 or EMS Platoon Shift Calendar have ads?

EMS Platoon Shift Calendar shows ads; O2gO2 does not.

### Which is updated more often, O2gO2 or EMS Platoon Shift Calendar?

O2gO2 ships an update every 28 months, and EMS Platoon Shift Calendar every 2 months. Most recently, O2gO2 was updated on October 19, 2026 and EMS Platoon Shift Calendar on October 24, 2026.

---

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