# Celestia vs Big Number Calculator+

The clearest difference is review sentiment: Celestia at 78% against Big Number Calculator+'s 0%. Celestia also leads on rating (4.4 vs 3.7) and update cadence (every 2 weeks vs every 4 months). Big Number Calculator+'s advantage is in-app purchases (none vs 4) and iOS requirement (13.0 vs 15.0). On price, ads and device support there is nothing between them.

Both are free to download. Celestia sells 4 in-app purchases, starting at $0.99 per 7 days. Big Number Calculator+ asks for nothing beyond the download.

Celestia holds the better App Store score, 4.4 against 3.7. That said, the two scores are not equally well evidenced: Celestia has 324 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 78% of Celestia's written reviews are positive against 0% of Big Number Calculator+'s.

Celestia ships an update every 2 weeks, Big Number Calculator+ every 4 months. The most recent releases landed on September 21, 2026 and June 4, 2026 respectively.

## The numbers

| Metric | Celestia | Big Number Calculator+ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (324 ratings)](https://appshunter.io/ios/app/celestia-space-simulator/id1500434829/reviews)** | [3.7 (3 ratings)](https://appshunter.io/ios/app/big-number-calculator-plus/id1541255205/reviews) |
| Number of ratings | **324** | 3 |
| Positive reviews | **78.3% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 4 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 545 MB | 19 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [林峰 李](https://appshunter.io/developer/1186547508) | [Kunio Takeuchi](https://appshunter.io/developer/851499887) |

## What reviewers say

### Celestia

[App page](https://appshunter.io/ios/app/celestia-space-simulator/id1500434829)

Explore the universe in real-time 3D. Visit planets, moons, star clusters, and galaxies, viewing them from any point in space and time. Customize your experience with expandable content and detailed simulations.

**Highlights:** Real-time 3D space visualization, Explore planets, moons, stars, galaxies, Accurate solar system object positions, Interactive planetarium mode, Expandable content with add-ons, Customizable celestial databases

**Features:** Game Controller support, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Celestia PLUS (Weekly) | $0.99 | per 7 days |
| Celestia PLUS (Monthly) | $1.99 | per month |
| Celestia PLUS (Yearly) | $19.99 | per year |
| Celestia PLUS (Lifetime) | $79.99 | one-time |

**What reviewers like**

- ⭐ Realistic space simulation
- 🌌 Ability to explore galaxies and star systems
- 🔍 Detailed planet and moon textures
- 📷 Great for taking screenshots
- 🤖 Reminds users of Space Engine

**What reviewers complain about**

- 🐛 Occasional crashes and glitches
- 🌌 Limited exploration beyond Milky Way and Andromeda
- 🌍 Flat terrain on planets
- 🔍 Lack of detail on some celestial objects
- 🔒 Paywall for some features

**Reported bugs**

- Milky Way and other galaxy textures not loading properly
- Crashes when using certain add-ons
- Issues with planet and moon orbits not being accurate

**Requested features**

- Add more exoplanets and distant star systems
- Implement terrain generation for planets
- Expand to include more galaxies and the overall universe structure
- Add support for black holes, pulsars, and other exotic objects
- Improve controls and camera movement


### Big Number Calculator+

[App page](https://appshunter.io/ios/app/big-number-calculator-plus/id1541255205)

Perform calculations with extremely large numbers, up to 66,000 digits. Supports addition, subtraction, multiplication, and division, with options for different calculation engines and data input methods. Results can be saved and printed in formatted text files.

**Highlights:** Handles up to 66,000 digits, Addition, subtraction, multiplication, division, Selectable calculation engines (Swift, Objective-C), Load data from files (txt, rtf, rtfd), Automatic data formatting for printing and saving, Customizable number separators

**In-app purchases:** none


## Frequently asked questions

### Is Celestia free?

Celestia is free to download, with in-app purchases available.

### Is Big Number Calculator+ free?

Big Number Calculator+ is free to download, with no in-app purchases.

### Which has better reviews, Celestia or Big Number Calculator+?

Celestia is rated higher. Celestia averages 4.4 out of 5 from 324 ratings, while Big Number Calculator+ averages 3.7 from 3 ratings.

### Do Celestia or Big Number Calculator+ have ads?

Neither Celestia nor Big Number Calculator+ shows ads.

### Which is updated more often, Celestia or Big Number Calculator+?

Celestia ships an update every 2 weeks, and Big Number Calculator+ every 4 months. Most recently, Celestia was updated on September 21, 2026 and Big Number Calculator+ on June 4, 2026.

---

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