# Comet Book vs DISCS

The clearest difference is rating: Comet Book at 5.0 against DISCS's 2.0. DISCS's advantage is update cadence (every 2 months vs every 6 months) and iOS requirement (8.0 vs 12.0). On price, review sentiment, ratings volume and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Comet Book holds the better App Store score, 5.0 against 2.0. Both are backed by a comparable volume of ratings — 3 and 3 respectively. Written reviews point the same way: 55% of Comet Book's written reviews are positive against 50% of DISCS's.

Comet Book ships an update every 6 months, DISCS every 2 months. The most recent releases landed on October 23, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Comet Book | DISCS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/comet-book/id604782335/reviews)** | [2.0 (3 ratings)](https://appshunter.io/ios/app/discs-drought-information/id1287105143/reviews) |
| Number of ratings | 3 | 3 |
| Positive reviews | **54.9% of reviews** | 50.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 10 MB | 54 MB |
| Requires iOS | 12.0 | **8.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 9+ | 4+ |
| Developer | [Vixen Co.,Ltd.](https://appshunter.io/developer/536188843) | [NASA](https://appshunter.io/developer/355542146) |

## What reviewers say

### Comet Book

[App page](https://appshunter.io/ios/app/comet-book/id604782335)

Discover and track comets with this educational app. It provides real-time direction and elevation data to help you locate celestial objects in the night sky. Explore the solar system in 3D and visualize the movement of comets and planets.

**Highlights:** Comet viewing direction and elevation, Real-time celestial object tracking, 3D Solar System mode, Visualize comet and planet motion, Observing site guidance

**In-app purchases:** none


### DISCS

[App page](https://appshunter.io/ios/app/discs-drought-information/id1287105143)

Contribute observations about local crop conditions and drought impacts to a scientific community. View your reports alongside data from NASA satellites, NOAA rainfall, and ground sensors.

**Highlights:** Report crop conditions, Upload photos, View drought data, See rainfall information, Monitor vegetation health, Observe satellite data

**In-app purchases:** none


## Frequently asked questions

### Is Comet Book free?

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

### Is DISCS free?

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

### Which has better reviews, Comet Book or DISCS?

Comet Book is rated higher. Comet Book averages 5.0 out of 5 from 3 ratings, while DISCS averages 2.0 from 3 ratings.

### Do Comet Book or DISCS have ads?

Neither Comet Book nor DISCS shows ads.

### Which is updated more often, Comet Book or DISCS?

Comet Book ships an update every 6 months, and DISCS every 2 months. Most recently, Comet Book was updated on October 23, 2026 and DISCS on October 1, 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.*