# ZERO CARBON TH vs NAPA

The clearest difference is update cadence: ZERO CARBON TH at every 3 weeks against NAPA's every 2 months. On price, ads, 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.

ZERO CARBON TH ships an update every 3 weeks, NAPA every 2 months. The most recent releases landed on September 23, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | ZERO CARBON TH | NAPA |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (3 ratings)](https://appshunter.io/ios/app/napa-star-map/id6475964108/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | — | 75.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | — | Free |
| Size | 49 MB | 287 MB |
| Requires iOS | 12 | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Thailand Greenhouse Gas Management Organization](https://appshunter.io/developer/938564036) | [National Astronomical Research Institute of Thailand (Public Organization)](https://appshunter.io/developer/1725468782) |

## What reviewers say

### ZERO CARBON TH

[App page](https://appshunter.io/ios/app/zero-carbon-th/id6468645997)

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

**In-app purchases:** none


### NAPA

[App page](https://appshunter.io/ios/app/napa-star-map/id6475964108)

Explore the night sky with this astronomy and planetarium app. Identify stars, constellations, and planets by pointing your device at the sky. Plan future observations by adjusting the time and date.

**Highlights:** Point and observe celestial objects, Star map functionality, Time adjustment for observation planning, Simulate planet positions, Locate specific celestial objects, Real images of deep sky objects

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ZERO CARBON TH free?

ZERO CARBON TH is free to download, with no in-app purchases.

### Is NAPA free?

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

### Do ZERO CARBON TH or NAPA have ads?

Neither ZERO CARBON TH nor NAPA shows ads.

### Which is updated more often, ZERO CARBON TH or NAPA?

ZERO CARBON TH ships an update every 3 weeks, and NAPA every 2 months. Most recently, ZERO CARBON TH was updated on September 23, 2026 and NAPA on September 7, 2026.

---

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