# SolarZero vs Pure Clock for older systems

The clearest difference is iOS requirement: Pure Clock for older systems at 15.6 against SolarZero's 17.0. 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.

## The numbers

| Metric | SolarZero | Pure Clock for older systems |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 35.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | — |
| Monetization | Free | — |
| Size | 22 MB | 2 MB |
| Requires iOS | 17.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [solarZero Limited](https://appshunter.io/developer/1283894275) | [Sheng Zhao](https://appshunter.io/developer/1878542823) |

## What reviewers say

### SolarZero

[App page](https://appshunter.io/ios/app/solarzero/id6504657190)

Monitor and optimize your home's solar energy system with real-time data on energy generation and usage. Track carbon savings, access energy-saving modes, and refer friends to the service.

**Highlights:** Real-time energy generation and usage data, Energy import/export status updates, Carbon savings and footprint tracking, Hot water energy saving mode, Refer-a-Friend program

**In-app purchases:** none


### Pure Clock for older systems

[App page](https://appshunter.io/ios/app/pure-clock-for-older-systems/id6760163576)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SolarZero free?

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

### Is Pure Clock for older systems free?

Pure Clock for older systems is free to download, with no in-app purchases.

### Do SolarZero or Pure Clock for older systems have ads?

Neither SolarZero nor Pure Clock for older systems shows ads.

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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.*