# CO2 Tracker vs Be Underwater

The clearest difference is ads: CO2 Tracker at none against Be Underwater's shown. CO2 Tracker also leads on monetization model (free vs free with in-app purchases) and ratings volume (3 vs 1). Be Underwater's advantage is update cadence (every 10 days vs every 3 months). On price, rating, in-app purchases and device support there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for CO2 Tracker against 5.0 for Be Underwater. Both are backed by a comparable volume of ratings — 3 and 1 respectively.

CO2 Tracker ships an update every 3 months, Be Underwater every 10 days. The most recent releases landed on October 15, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | CO2 Tracker | Be Underwater |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (3 ratings)](https://appshunter.io/ios/app/co2-tracker/id1459765187/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/be-underwater/id6762518252/reviews) |
| Number of ratings | **3** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | **Every 10 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 11 MB | 45 MB |
| Requires iOS | **12.1** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Madhu Raghavan](https://appshunter.io/developer/1459765186) | [Eliana Jordan](https://appshunter.io/developer/1871934481) |

## What reviewers say

### CO2 Tracker

[App page](https://appshunter.io/ios/app/co2-tracker/id1459765187)

Calculate the carbon dioxide output of your flights by entering your departure and arrival cities. Understand the environmental impact of your travel and make more responsible decisions to help protect the planet.

**Highlights:** Calculate flight CO2 output, Enter departure and arrival cities, Select from 40 aircraft types, Determine flight distance, View percentage of annual safe CO2 output

**Features:** macOS Compatibility

**In-app purchases:** none


### Be Underwater

[App page](https://appshunter.io/ios/app/be-underwater/id6762518252)

Discover and book dive courses, trips, and liveaboards worldwide. Compare prices, itineraries, and operators for your next underwater adventure. Find the perfect dive sites and plan your diving experiences easily.

**Highlights:** Book dive courses worldwide, Find liveaboard trips, Compare dive site destinations, Compare prices and operators, Save favorite adventures, Interactive dive map

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

**In-app purchases:** none


## Frequently asked questions

### Is CO2 Tracker free?

CO2 Tracker is free to download, with no in-app purchases.

### Is Be Underwater free?

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

### Which has better reviews, CO2 Tracker or Be Underwater?

CO2 Tracker and Be Underwater are both rated 5.0 out of 5 on the App Store, from 3 and 1 ratings respectively.

### Do CO2 Tracker or Be Underwater have ads?

Be Underwater shows ads; CO2 Tracker does not.

### Which is updated more often, CO2 Tracker or Be Underwater?

CO2 Tracker ships an update every 3 months, and Be Underwater every 10 days. Most recently, CO2 Tracker was updated on October 15, 2026 and Be Underwater on October 2, 2026.

---

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