# iStellar vs Altimeter for Aviators

The clearest difference is price: Altimeter for Aviators at Free against iStellar's $3.99. Altimeter for Aviators also leads on rating (4.7 vs 4.0) and review sentiment (76% vs 49%). iStellar's advantage is in-app purchases (none vs 2) and chart position (#156 vs unranked). On ads and iOS requirement there is nothing between them.

Altimeter for Aviators is free to download; iStellar costs $3.99 up front. Altimeter for Aviators sells 2 one-off in-app purchases. iStellar asks for nothing beyond the download.

Altimeter for Aviators holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Altimeter for Aviators has 583 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 49% of iStellar's written reviews are positive against 76% of Altimeter for Aviators's.

iStellar ships an update every 3 months, Altimeter for Aviators every 5 weeks. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | iStellar | Altimeter for Aviators |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/istellar/id293118835/reviews) | **[4.7 (583 ratings)](https://appshunter.io/ios/app/altimeter-for-aviators/id1463100680/reviews)** |
| Number of ratings | 1 | **583** |
| Positive reviews | 49.3% of reviews | **75.6% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 5 weeks** |
| Monetization | Paid | **Free with in-app purchases** |
| Best chart rank | **#156** | — |
| Size | 37 MB | 2 MB |
| Requires iOS | 12.4 | **12.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | +4 |
| Developer | [AstroArts Inc.](https://appshunter.io/developer/293118838) | [STEARsoft](https://appshunter.io/developer/373730382) |

## What reviewers say

### iStellar

[App page](https://appshunter.io/ios/app/istellar/id293118835)

**Currently charting:** #156 Top Paid · Navigation (US App Store)

Explore the cosmos with a realistic planetarium experience. View the night sky from any location and time, with detailed celestial bodies and dynamic simulations. Intuitive multi-touch controls make navigation effortless.

**Highlights:** Real-time starry sky simulation, Adjustable location and time, Detailed celestial object data, Intuitive multi-touch controls, Solar eclipse simulation, Object search function

**Features:** Vision Pro support

**In-app purchases:** none


### Altimeter for Aviators

[App page](https://appshunter.io/ios/app/altimeter-for-aviators/id1463100680)

This app functions as a pressure altimeter, similar to those found in aircraft, utilizing your device's barometer. It's designed for pilots and aviation enthusiasts to understand altitude, height above a location, and flight levels. It works as a standalone Apple Watch app or on iPhones/iPads with a barometer.

**Highlights:** Pressure altimeter functionality, Standalone Apple Watch app, Calculates altitude above sea level, Calculates height above a specific location (QFE), Calculates Flight Level (FL) using standard pressure, Supports pressure units (inHg, hPa, mb)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| VSI | $1.99 | one-time |
| Altitude Units | $1.99 | one-time |

**What reviewers like**

- 👍 Simple and intuitive user interface
- ✈️ Accurate altimeter representation for pilots
- ⌚ Works well on Apple Watch
- 🎯 Easy pressure setting adjustment like real cockpit
- 📱 No GPS required for operation

**What reviewers complain about**

- 🐛 App crashes or stops working after iOS updates
- 📵 Inconsistent performance across Watch models
- 🔴 Watch display shows red/no reading on some devices
- 📧 Poor developer communication and contact options
- 💰 Upsell prompts not clearly disclosed

**Reported bugs**

- App hangs on 'reading pressure' with Apple Watch 8
- Watch complication shows dashed line instead of altitude
- Incompatibility with iOS 17.4
- Watch app graphics fuzzy/wrong resolution
- Crown and long press unresponsive on Watch 8

**Requested features**

- CarPlay integration and widget support
- Night mode with dark theme
- Keep screen on while flying option
- Drum pointer altimeter display option
- Digital altitude readout option


## Frequently asked questions

### Is iStellar free?

iStellar costs $3.99, with no in-app purchases.

### Is Altimeter for Aviators free?

Altimeter for Aviators is free to download, with in-app purchases available.

### Which has better reviews, iStellar or Altimeter for Aviators?

Altimeter for Aviators is rated higher. iStellar averages 4.0 out of 5 from 1 ratings, while Altimeter for Aviators averages 4.7 from 583 ratings.

### Do iStellar or Altimeter for Aviators have ads?

Neither iStellar nor Altimeter for Aviators shows ads.

### Which is updated more often, iStellar or Altimeter for Aviators?

iStellar ships an update every 3 months, and Altimeter for Aviators every 5 weeks. Most recently, iStellar was updated on October 24, 2026 and Altimeter for Aviators on October 25, 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.*