# ETPhone vs Calculator with reverse screen

The clearest difference is ads: ETPhone at none against Calculator with reverse screen's shown. Calculator with reverse screen's advantage is update cadence (fortnightly vs every 16 months). On price, in-app purchases, device support and iOS requirement there is nothing between them.

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

ETPhone ships an update every 16 months, Calculator with reverse screen fortnightly. The most recent releases landed on October 10, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | ETPhone | Calculator with reverse screen |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (6 ratings)](https://appshunter.io/ios/app/etphone/id1529643726/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 16 months | **Fortnightly** |
| Monetization | Free | — |
| Size | 1 MB | 35 MB |
| Requires iOS | 16 | **15.8.3** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Argus Science, LLC](https://appshunter.io/developer/1529643728) | [Hideaki Uchikoshi](https://appshunter.io/developer/1559575002) |

## What reviewers say

### ETPhone

[App page](https://appshunter.io/ios/app/etphone/id1529643726)

This application enables real-time gaze computation and recording for eye tracking data collection using a compatible wearable device. It offers control over camera settings, participant calibration, and data recording to an SD card. Collected data can be easily transferred for detailed analysis on a PC.

**Highlights:** Real-time gaze computation, Gaze data recording, Camera gain and quality control, Participant calibration, SD card recording control, Data download for PC analysis

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

**In-app purchases:** none


### Calculator with reverse screen

[App page](https://appshunter.io/ios/app/calculator-with-reverse-screen/id6497792768)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ETPhone free?

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

### Is Calculator with reverse screen free?

Calculator with reverse screen is free to download, with no in-app purchases.

### Do ETPhone or Calculator with reverse screen have ads?

Calculator with reverse screen shows ads; ETPhone does not.

### Which is updated more often, ETPhone or Calculator with reverse screen?

ETPhone ships an update every 16 months, and Calculator with reverse screen fortnightly. Most recently, ETPhone was updated on October 10, 2026 and Calculator with reverse screen on October 4, 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.*