# CO2 Modeller vs Moya Chinese Flashcards

The clearest difference is in-app purchases: CO2 Modeller at none against Moya Chinese Flashcards's 2. CO2 Modeller also leads on iOS requirement (12.1 vs 15.1). Moya Chinese Flashcards's advantage is update cadence (every 10 days vs every 36 months) and review sentiment (100% vs 75%). On price, ads and device support there is nothing between them.

Both are free to download. Moya Chinese Flashcards sells 2 in-app purchases, starting at $1.99 per month. CO2 Modeller asks for nothing beyond the download.

CO2 Modeller ships an update every 36 months, Moya Chinese Flashcards every 10 days. The most recent releases landed on November 2, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | CO2 Modeller | Moya Chinese Flashcards |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.5 (2 ratings)](https://appshunter.io/ios/app/co2-modeller/id1037101261/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 75.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 36 months | **Every 10 days** |
| Monetization | **Free** | Freemium |
| Size | 9 MB | 139 MB |
| Requires iOS | **12.1** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Alex Rogers](https://appshunter.io/developer/346832869) | [Moya Labs](https://appshunter.io/developer/1878696700) |

## What reviewers say

### CO2 Modeller

[App page](https://appshunter.io/ios/app/co2-modeller/id1037101261)

Simulate the impact of reducing carbon emissions on climate change. This app generates projections for atmospheric CO2 concentration, global warming, sea level rise, and ocean acidification.

**Highlights:** Model carbon emission reductions, Simulate climate change effects, Project CO2 concentration, Estimate global warming, Predict sea level rise, Analyze ocean acidification

**Features:** macOS Compatibility

**In-app purchases:** none


### Moya Chinese Flashcards

[App page](https://appshunter.io/ios/app/moya-chinese-flashcards/id6759454887)

Master Mandarin with daily flashcards, quizzes, and spaced repetition. Build a consistent learning habit with streak tracking and gamified progress. Offers multiple study modes and HSK vocabulary lists for structured learning.

**Highlights:** Spaced repetition system (SRS), Multiple study modes, HSK vocabulary lists, Daily review and streak tracking, Offline learning, Gamified progress with bamboo plant

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Moya Chinese Premium | $1.99 | per month |
| Moya Chinese Premium | $6.99 | per year |


## Frequently asked questions

### Is CO2 Modeller free?

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

### Is Moya Chinese Flashcards free?

Moya Chinese Flashcards is free to download, with in-app purchases available.

### Do CO2 Modeller or Moya Chinese Flashcards have ads?

Neither CO2 Modeller nor Moya Chinese Flashcards shows ads.

### Which is updated more often, CO2 Modeller or Moya Chinese Flashcards?

CO2 Modeller ships an update every 36 months, and Moya Chinese Flashcards every 10 days. Most recently, CO2 Modeller was updated on November 2, 2026 and Moya Chinese Flashcards on October 31, 2026.

---

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