# ABBIDOT GPS Pet Tracker vs E2M (Engineer with EM waves)

The clearest difference is in-app purchases: ABBIDOT GPS Pet Tracker at none against E2M (Engineer with EM waves)'s 3. ABBIDOT GPS Pet Tracker also leads on update cadence (weekly vs fortnightly) and iOS requirement (15.6 vs 17.6). E2M (Engineer with EM waves)'s advantage is review sentiment (100% vs 90%). 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. ABBIDOT GPS Pet Tracker asks for nothing beyond the download.

ABBIDOT GPS Pet Tracker ships an update weekly, E2M (Engineer with EM waves) fortnightly. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | ABBIDOT GPS Pet Tracker | E2M (Engineer with EM waves) |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (7 ratings)](https://appshunter.io/ios/app/abbidot-gps-pet-tracker/id6446677568/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | 90.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Weekly** | Fortnightly |
| Monetization | **Free** | Freemium |
| Size | 91 MB | 80 MB |
| Requires iOS | **15.6** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Shanren Technology Co., Ltd.](https://appshunter.io/developer/1211546028) | [ComPhysics](https://appshunter.io/developer/1821978540) |

## What reviewers say

### ABBIDOT GPS Pet Tracker

[App page](https://appshunter.io/ios/app/abbidot-gps-pet-tracker/id6446677568)

This app pairs with a GPS tracker to provide real-time location updates for pets. It offers custom geofencing with alerts, activity logs, and the ability to share your pet's location with family.

**Highlights:** Real-time GPS tracking, Custom geofencing with alerts, Activity and resting logs, 15 days of history routes, Family member sharing

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

**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 ABBIDOT GPS Pet Tracker free?

ABBIDOT GPS Pet Tracker 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 ABBIDOT GPS Pet Tracker or E2M (Engineer with EM waves) have ads?

Neither ABBIDOT GPS Pet Tracker nor E2M (Engineer with EM waves) shows ads.

### Which is updated more often, ABBIDOT GPS Pet Tracker or E2M (Engineer with EM waves)?

ABBIDOT GPS Pet Tracker ships an update weekly, and E2M (Engineer with EM waves) fortnightly. Most recently, ABBIDOT GPS Pet Tracker was updated on November 3, 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.*