# Hormones. vs Solar Book

The clearest difference is price: Solar Book at Free against Hormones.'s $0.99. Solar Book also leads on update cadence (every 14 months vs every 34 months) and device support (3 vs 1). On ads, in-app purchases and iOS requirement there is nothing between them.

Solar Book is free to download; Hormones. costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Hormones. ships an update every 34 months, Solar Book every 14 months. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Hormones. | Solar Book |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | — | **[4.8 (4 ratings)](https://appshunter.io/ios/app/solar-book/id1078873201/reviews)** |
| Number of ratings | — | **4** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 34 months | **Every 14 months** |
| Monetization | — | Free |
| Size | 620 MB | 5 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [www.ajaxmediatech.com](https://appshunter.io/developer/973768003) | [Vixen Co.,Ltd.](https://appshunter.io/developer/536188843) |

## What reviewers say

### Hormones.

[App page](https://appshunter.io/ios/app/hormones/id1011680844)

**Features:** macOS Compatibility

**In-app purchases:** none


### Solar Book

[App page](https://appshunter.io/ios/app/solar-book/id1078873201)

This app provides detailed information about solar eclipses, including timings for different phases based on your location. It allows you to view sequential images and star charts for planning and observation.

**Highlights:** Solar eclipse phase timing, Location-based eclipse calculations, Sequential eclipse image display, Star chart visualization, Past and future eclipse planning

**In-app purchases:** none


## Frequently asked questions

### Is Hormones. free?

Hormones. costs $0.99, with no in-app purchases.

### Is Solar Book free?

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

### Do Hormones. or Solar Book have ads?

Neither Hormones. nor Solar Book shows ads.

### Which is updated more often, Hormones. or Solar Book?

Hormones. ships an update every 34 months, and Solar Book every 14 months. Most recently, Hormones. was updated on October 26, 2026 and Solar Book on October 24, 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.*