# iAltair vs e

The clearest difference is ratings volume: iAltair at 21 against e's 1. e's advantage is review sentiment (90% vs 75%) and rating (5.0 vs 4.8). On price, update cadence, ads and in-app purchases there is nothing between them.

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

e holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: iAltair has 21 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 75% of iAltair's written reviews are positive against 90% of e's.

Both ship on a similar rhythm, roughly every 11 months. The most recent releases landed on October 13, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | iAltair | e |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (21 ratings)](https://appshunter.io/ios/app/ialtair/id291182085/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/e-spacetime-converter/id291317973/reviews)** |
| Number of ratings | **21** | 1 |
| Positive reviews | 75.0% of reviews | **90.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 11 months | Every 11 months |
| Monetization | Free | Free |
| Size | 10 MB | 4 MB |
| Requires iOS | **15.4** | 15.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Peter Schorn](https://appshunter.io/developer/291182088) | [Elliptics, Ltd.](https://appshunter.io/developer/289108972) |

## What reviewers say

### iAltair

[App page](https://appshunter.io/ios/app/ialtair/id291182085)

Experience vintage computing with a simulation of the MITS Altair 8800. Explore old software like CP/M 2 and run programs such as Eliza using built-in BASIC. This self-contained system offers a unique glimpse into early computing history.

**Highlights:** MITS Altair 8800 simulation, CP/M 2 operating system support, Built-in BASIC interpreter, Run Eliza program, Self-contained system

**In-app purchases:** none


### e

[App page](https://appshunter.io/ios/app/e-spacetime-converter/id291317973)

Explore the universe of spacetime by converting lengths into time and vice versa. This unique calculator uses geometrized units to help you think about the world in new ways and amuse your friends. It's a fun tool for science enthusiasts and students alike.

**Highlights:** Convert length to time, Convert time to length, Geometrized units (c=1), Avoids scientific notation, Supports various input units, Educational and entertaining

**In-app purchases:** none


## Frequently asked questions

### Is iAltair free?

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

### Is e free?

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

### Which has better reviews, iAltair or e?

e is rated higher. iAltair averages 4.8 out of 5 from 21 ratings, while e averages 5.0 from 1 ratings.

### Do iAltair or e have ads?

Neither iAltair nor e shows ads.

### Which is updated more often, iAltair or e?

iAltair ships an update every 11 months, and e every 11 months. Most recently, iAltair was updated on October 13, 2026 and e on October 5, 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.*