# zero vs Solar Shading Survey

The clearest difference is in-app purchases: zero at none against Solar Shading Survey's 2. zero also leads on iOS requirement (13.4 vs 17.6). Solar Shading Survey's advantage is update cadence (monthly vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. Solar Shading Survey sells 2 in-app purchases, starting at $3.99 per month. zero asks for nothing beyond the download.

zero ships an update every 4 months, Solar Shading Survey monthly. The most recent releases landed on September 14, 2026 and August 7, 2026 respectively.

## The numbers

| Metric | zero | Solar Shading Survey |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Monthly** |
| Size | 34 MB | 40 MB |
| Requires iOS | **13.4** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Cole Stites-Clayton](https://appshunter.io/developer/1734279918) | [Frederic Billon](https://appshunter.io/developer/1811407676) |

## What reviewers say

### zero

[App page](https://appshunter.io/ios/app/zero-carbon-agent/id6478878756)

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases:** none


### Solar Shading Survey

[App page](https://appshunter.io/ios/app/solar-shading-survey/id6785455749)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro | $3.99 | per month |
| Pro | $24.99 | per year |


## Frequently asked questions

### Is zero free?

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

### Is Solar Shading Survey free?

Solar Shading Survey is free to download, with in-app purchases available.

### Do zero or Solar Shading Survey have ads?

Neither zero nor Solar Shading Survey shows ads.

### Which is updated more often, zero or Solar Shading Survey?

zero ships an update every 4 months, and Solar Shading Survey monthly. Most recently, zero was updated on September 14, 2026 and Solar Shading Survey on August 7, 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.*