# Physics Toolbox Sensor Suite vs CO2 on Watch & Lockscreen

The clearest difference is rating: Physics Toolbox Sensor Suite at 4.7 against CO2 on Watch & Lockscreen's 1.0. Physics Toolbox Sensor Suite also leads on review sentiment (81% vs 50%) and ratings volume (1.8K vs 2). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Physics Toolbox Sensor Suite sells 1 one-off in-app purchase and CO2 on Watch & Lockscreen sells 8 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

Physics Toolbox Sensor Suite holds the better App Store score, 4.7 against 1.0. That said, the two scores are not equally well evidenced: Physics Toolbox Sensor Suite has 1.8K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 81% of Physics Toolbox Sensor Suite'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 October 18, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Physics Toolbox Sensor Suite | CO2 on Watch & Lockscreen |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (1.8K ratings)](https://appshunter.io/ios/app/physics-toolbox-sensor-suite/id1128914250/reviews)** | [1.0 (2 ratings)](https://appshunter.io/ios/app/co2-on-watch-and-lockscreen/id6738605498/reviews) |
| Number of ratings | **1.8K** | 2 |
| Positive reviews | **80.8% of reviews** | 50.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Weekly | Weekly |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 78 MB | 28 MB |
| Requires iOS | **16.0** | 17.6 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Chrystian Vieyra](https://appshunter.io/developer/998187453) | [Kevin Floch](https://appshunter.io/developer/1772752224) |

## What reviewers say

### Physics Toolbox Sensor Suite

[App page](https://appshunter.io/ios/app/physics-toolbox-sensor-suite/id1128914250)

This app turns your smartphone into a scientific instrument suite, enabling measurement, recording, analysis, and export of real-time sensor data. It offers tools for kinematics, acoustics, light, magnetism, and more, suitable for students, educators, researchers, and hobbyists.

**Highlights:** Real-time sensor data measurement, Data recording and analysis, Data export functionality, Kinematics tools (accelerometer, gyroscope), Acoustics tools (sound meter, oscilloscope), Magnetism tools (compass, magnetometer), AR visualization for magnetic fields and measurements

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade to Pro | $5.99 | one-time |


### 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 Physics Toolbox Sensor Suite free?

Physics Toolbox Sensor Suite is free to download, with in-app purchases available.

### Is CO2 on Watch & Lockscreen free?

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

### Which has better reviews, Physics Toolbox Sensor Suite or CO2 on Watch & Lockscreen?

Physics Toolbox Sensor Suite is rated higher. Physics Toolbox Sensor Suite averages 4.7 out of 5 from 1.8K ratings, while CO2 on Watch & Lockscreen averages 1.0 from 2 ratings.

### Do Physics Toolbox Sensor Suite or CO2 on Watch & Lockscreen have ads?

Neither Physics Toolbox Sensor Suite nor CO2 on Watch & Lockscreen shows ads.

### Which is updated more often, Physics Toolbox Sensor Suite or CO2 on Watch & Lockscreen?

Physics Toolbox Sensor Suite ships an update weekly, and CO2 on Watch & Lockscreen weekly. Most recently, Physics Toolbox Sensor Suite was updated on October 18, 2026 and CO2 on Watch & Lockscreen 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.*