# US Mobile vs CO2 on Watch & Lockscreen

The clearest difference is rating: US Mobile at 4.1 against CO2 on Watch & Lockscreen's 1.0. US Mobile also leads on in-app purchases (none vs 8) and ratings volume (2K vs 2). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. CO2 on Watch & Lockscreen sells 8 in-app purchases, starting at $3.99 per month. US Mobile asks for nothing beyond the download.

US Mobile holds the better App Store score, 4.1 against 1.0. That said, the two scores are not equally well evidenced: US Mobile has 2K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 68% of US Mobile's written reviews are positive against 50% of CO2 on Watch & Lockscreen's.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | US Mobile | CO2 on Watch & Lockscreen |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.1 (2K ratings)](https://appshunter.io/ios/app/us-mobile/id1460013401/reviews)** | [1.0 (2 ratings)](https://appshunter.io/ios/app/co2-on-watch-and-lockscreen/id6738605498/reviews) |
| Number of ratings | **2K** | 2 |
| Positive reviews | **68.0% of reviews** | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Weekly | Weekly |
| Monetization | **Free** | Free with in-app purchases |
| Size | 207 MB | 28 MB |
| Requires iOS | **16.4** | 17.6 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 17+ | 4+ |
| Developer | [US Mobile Inc.](https://appshunter.io/developer/1460013400) | [Kevin Floch](https://appshunter.io/developer/1772752224) |

## What reviewers say

### US Mobile

[App page](https://appshunter.io/ios/app/us-mobile/id1460013401)

Manage your mobile service with ease. Activate new lines, switch between major US networks, and track usage in real-time. Offers plans for individuals and families, with international data options and 24/7 support.

**Highlights:** Activate lines with eSIM or Starter Kit, Switch between major US networks, Manage individual and family plans, Add international data for travel, Monitor usage and balance, 24/7 human support

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Excellent service
- 👍 Great app experience
- 💡 Innovative features
- 🔒 Robust security
- 👍 User-friendly interface

**What reviewers complain about**

- 🐛 Buggy app
- 🔍 Missing features
- 🔍 Inconsistent data reporting
- 🔍 Complicated plan options
- 🔍 Unreliable international service

**Reported bugs**

- App freezes on login screen
- Inability to scroll on certain screens
- Incorrect data usage information
- Frequent app crashes and bugs
- eSIM compatibility issues

**Requested features**

- Improved data usage tracking
- Easier account management options
- Expanded international roaming support
- Parental controls and content filtering
- Seamless integration with Apple Watch


### CO2 on Watch & Lockscreen

[App page](https://appshunter.io/ios/app/co2-on-watch-and-lockscreen/id6738605498)

Monitor CO2 levels from compatible devices directly on your Apple Watch and iPhone Lock Screen. Receive smart alerts and view real-time air quality data with color-coded visuals for quick understanding.

**Highlights:** Apple Watch complications with history graph, iPhone Lock Screen widgets, Customizable CO2 threshold alerts, Background monitoring, Live Activity for real-time data, Color-coded air quality visuals

**Features:** macOS Compatibility

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| CO2_Monthly | $3.99 | per month |
| CO2_Annually | $29.99 | per year |
| Small tip | $4.99 | one-time |
| Medium tip | $9.99 | one-time |
| Large tip | $19.99 | one-time |
| CO2_Lifetime_Upgrade2 | $24.99 | one-time |
| CO2_Lifetime | $49.99 | one-time |
| Extra large tip | $49.99 | one-time |


## Frequently asked questions

### Is US Mobile free?

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

### Is CO2 on Watch & Lockscreen free?

CO2 on Watch & Lockscreen is free to download, with in-app purchases available.

### Which has better reviews, US Mobile or CO2 on Watch & Lockscreen?

US Mobile is rated higher. US Mobile averages 4.1 out of 5 from 2K ratings, while CO2 on Watch & Lockscreen averages 1.0 from 2 ratings.

### Do US Mobile or CO2 on Watch & Lockscreen have ads?

Neither US Mobile nor CO2 on Watch & Lockscreen shows ads.

### Which is updated more often, US Mobile or CO2 on Watch & Lockscreen?

US Mobile ships an update weekly, and CO2 on Watch & Lockscreen weekly. Most recently, US Mobile was updated on November 3, 2026 and CO2 on Watch & Lockscreen on October 30, 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.*