# The O2ptimaCM Checklist — CCR Checklist: O2ptima CM

> Digital rebreather assembly checklists with countdown timers and build summaries. (iPhone/iPad app by Andrew Austin.)

- Source: https://appshunter.io/ios/app/the-o2ptimacm-checklist/id6469104578 (this page in markdown: same URL + `.md`)
- Developer: [Andrew Austin](https://appshunter.io/developer/1708589155)
- Category: Sports
- Price: $9.99 with in-app purchases
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: +4
- Requires: iOS 17.0 · 2 MB
- Languages: American English
- Released: 2023-10-12
- Data updated: 2026-08-18
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/the-o2ptimacm-checklist/id6469104578/reviews.md

## What is The O2ptimaCM Checklist?

The O2ptima CM Checklist app simplifies rebreather assembly with dedicated checklists mirroring the manual lists. Set precise countdown timers for Positive, Negative, and Pre-breathes. Summary view of your build with caution blocks if steps are missed. Manage your build from a simple digital checklist! Help save the planet by moving away from throw away paper every time you dive to a digital checklist in your phone or Ipad!

## Key features

- Digital rebreather assembly checklists
- Countdown timers for breathing stages
- Summary view of build progress
- Caution blocks for missed steps
- Paperless dive preparation

## Pricing and in-app purchases

Base price: $9.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Tiny Tip | $0.99 | one-time |
| Small Tip | $1.99 | one-time |
| Medium Tip | $4.99 | one-time |
| Large Tip | $9.99 | one-time |



## Frequently asked questions about The O2ptimaCM Checklist

### What is O2ptimaCM Checklist?

O2ptimaCM Checklist is a digital tool designed to simplify the assembly of rebreathers for divers. It provides step-by-step checklists and timers to ensure a safe and efficient build process.

### What are the main features of O2ptimaCM Checklist?

Key features include digital checklists that mirror manual lists, precise countdown timers for Positive, Negative, and Pre-breathes, and a summary view that highlights any missed steps with caution blocks.

### How much does O2ptimaCM Checklist cost?

O2ptimaCM Checklist is a paid application, available for $9.99. This one-time purchase grants you access to all its features for managing your rebreather builds.

### Does O2ptimaCM Checklist have ads?

No, O2ptimaCM Checklist is ad-free. As a paid application, it focuses on providing a seamless and uninterrupted user experience without advertisements.

### What devices is O2ptimaCM Checklist available on?

O2ptimaCM Checklist is compatible with both iPhone and iPad devices, allowing divers to manage their checklists on their preferred Apple mobile device.

### How often is O2ptimaCM Checklist updated?

The app was last updated on January 21, 2025, indicating active development and support. Updates typically include improvements and new features based on user feedback and evolving diving standards.

### What is the age rating for O2ptimaCM Checklist?

O2ptimaCM Checklist has an age rating of 4+, making it suitable for users of all ages. This rating reflects the app's content and its general accessibility.

### What is the user sentiment for O2ptimaCM Checklist?

Based on the available rating, O2ptimaCM Checklist has received overwhelmingly positive feedback, with a perfect 5.0 stars from one rating. This suggests a high level of user satisfaction with its functionality and ease of use.

## Version history (last 4 releases)

### 1.6 — 2025-01-21

- New Feature based on feedback. User can now change their low setpoint in settings.
- Minor UI enhancements
- Please leave feedback for more feature requests on ideasandbugz.com

### 1.5 — 2024-05-09

This update includes
- minor bug fixes and enhancements
- New Cell Chart that shows mV reading on Air and O2
- Cell expiration date

### 1.2 — 2024-02-03

This update includes
- minor bug fixes and enhancements
- New Cell Chart that shows mV reading on Air and O2
- Sortable build history
- Gear Checklist with notifications

### 1.0 — 2023-10-12

No release notes.

## Apps similar to The O2ptimaCM Checklist

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Halcyon Dive Systems - Diving](https://appshunter.io/ios/app/halcyon-dive-systems-diving/id6738069654) | 5.0 (8) | Free | Sports |
| [Trimix Tools](https://appshunter.io/ios/app/trimix-tools/id289220808) | 5.0 (5) | $6.99 | Sports |
| [DecoPlanner mobile](https://appshunter.io/ios/app/decoplanner-mobile/id1580563324) | — | Free | Sports |
| [Subsurface-mobile](https://appshunter.io/ios/app/subsurface-mobile/id1093217161) | 4.5 (46) | Free | Sports |
| [SUEX Calypso](https://appshunter.io/ios/app/suex-calypso/id1478705852) | — | Free | Sports |
| [O'Dive](https://appshunter.io/ios/app/odive/id1534593720) | 5.0 (1) | Free | Sports |

## More apps by Andrew Austin

- [The JJ CCR Checklist: Diving](https://appshunter.io/ios/app/the-jj-ccr-checklist-diving/id6467408738)
- [The Xccr Checklist: Diving](https://appshunter.io/ios/app/the-xccr-checklist-diving/id6467408753)
- [SOS: France](https://appshunter.io/ios/app/sos-france/id6468307505)
- [Pelagian CCR Checklist](https://appshunter.io/ios/app/pelagian-ccr-checklist/id6468662833)
- [The T-Reb Checklist](https://appshunter.io/ios/app/the-t-reb-checklist/id6471980731)

All apps by Andrew Austin: https://appshunter.io/developer/1708589155

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-18.*