# DifCal vs Solar Orrery

The clearest difference is update cadence: Solar Orrery at every 3 weeks against DifCal's every 15 months. DifCal's advantage is iOS requirement (12.0 vs 15.0). 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.

DifCal ships an update every 15 months, Solar Orrery every 3 weeks. The most recent releases landed on November 1, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | DifCal | Solar Orrery |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/solar-orrery/id6768309076/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Every 3 weeks** |
| Monetization | — | Free |
| Size | 9 MB | 35 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sean Brennan](https://appshunter.io/developer/898026482) | [LanguageCraft](https://appshunter.io/developer/1029635130) |

## What reviewers say

### DifCal

[App page](https://appshunter.io/ios/app/difcal/id898026479)

**Features:** Vision Pro support

**In-app purchases:** none


### Solar Orrery

[App page](https://appshunter.io/ios/app/solar-orrery/id6768309076)

Explore a real-time, interactive model of our solar system and the night sky. Journey through planets, moons, stars, and constellations with cinematic visuals and intuitive controls. Track celestial objects and experience the vastness of space.

**Highlights:** Interactive solar system model, Real-time orbital data, 41,000+ stars and constellations, Time controls for simulation, Touch-first camera controls, Colorblind-accessible themes, Live celestial object feeds

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is DifCal free?

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

### Is Solar Orrery free?

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

### Do DifCal or Solar Orrery have ads?

Neither DifCal nor Solar Orrery shows ads.

### Which is updated more often, DifCal or Solar Orrery?

DifCal ships an update every 15 months, and Solar Orrery every 3 weeks. Most recently, DifCal was updated on November 1, 2026 and Solar Orrery on October 31, 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.*