# NB vs E2M (Engineer with EM waves)

The clearest difference is in-app purchases: NB at none against E2M (Engineer with EM waves)'s 3. NB also leads on iOS requirement (13.0 vs 17.6). E2M (Engineer with EM waves)'s advantage is update cadence (fortnightly vs every 8 months). On price, ads and device support there is nothing between them.

Both are free to download. E2M (Engineer with EM waves) sells 3 in-app purchases, starting at $7.99 per month. NB asks for nothing beyond the download.

NB ships an update every 8 months, E2M (Engineer with EM waves) fortnightly. The most recent releases landed on November 4, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | NB | E2M (Engineer with EM waves) |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Fortnightly** |
| Monetization | — | Freemium |
| Size | 18 MB | 80 MB |
| Requires iOS | **13.0** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Steamrock Inc.](https://appshunter.io/developer/1705604272) | [ComPhysics](https://appshunter.io/developer/1821978540) |

## What reviewers say

### NB

[App page](https://appshunter.io/ios/app/nb-42-barometer/id6503903082)

**In-app purchases:** none


### E2M (Engineer with EM waves)

[App page](https://appshunter.io/ios/app/e2m-engineer-with-em-waves/id6747601796)

This app is a 1D electromagnetic and optics simulator for iOS devices. It allows engineers, researchers, and students to analyze layered structures, extract photonic bands, and simulate optical properties with advanced polarization control and material libraries.

**Highlights:** 1D EM solver for layered structures, Reflectance, Transmittance, Absorptance analysis, Arbitrary polarization state analysis, Photonic band structure extraction, Integrated material library (refractiveindex.info), User-defined materials, Data export (.csv, figures)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Standard: 1 month subscription | $7.99 | per month |
| Standard: 1 year subscription | $79.99 | per year |
| E2M Lifetime License | $239.99 | one-time |


## Frequently asked questions

### Is NB free?

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

### Is E2M (Engineer with EM waves) free?

E2M (Engineer with EM waves) is free to download, with in-app purchases available.

### Do NB or E2M (Engineer with EM waves) have ads?

Neither NB nor E2M (Engineer with EM waves) shows ads.

### Which is updated more often, NB or E2M (Engineer with EM waves)?

NB ships an update every 8 months, and E2M (Engineer with EM waves) fortnightly. Most recently, NB was updated on November 4, 2026 and E2M (Engineer with EM waves) on October 30, 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.*