# The Master Key System vs AI Lie Detector.

The clearest difference is in-app purchases: AI Lie Detector. at none against The Master Key System's 1. The Master Key System's advantage is review sentiment (25% vs 0%) and iOS requirement (8.0 vs 17.0). On price, ads, monetization model and device support there is nothing between them.

Both are free to download. The Master Key System sells 1 one-off in-app purchase. AI Lie Detector. asks for nothing beyond the download.

## The numbers

| Metric | The Master Key System | AI Lie Detector. |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.3 (7 ratings)](https://appshunter.io/ios/app/the-master-key-system-audio/id1380717052/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | **25.0% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | — | Every 2 days |
| Monetization | Free | Free |
| Size | 49 MB | 12 MB |
| Requires iOS | **8.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Huong Nguyen](https://appshunter.io/developer/1342162705) | [GKUER](https://appshunter.io/developer/1623974660) |

## What reviewers say

### The Master Key System

[App page](https://appshunter.io/ios/app/the-master-key-system-audio/id1380717052)

This application provides an audio version of "The Master Key System," a personal development book focusing on New Thought principles. It features synchronized narration, allowing users to read and listen simultaneously, with exercises and Q&A sections for each chapter.

**Highlights:** Synchronized audio narration, Chapter exercises and Q&A, Adjustable font size and style, Night and day reading modes, Background audio playback, Text highlighting

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All | $0.99 | one-time |


### AI Lie Detector.

[App page](https://appshunter.io/ios/app/ai-lie-detector/id6746071721)

Engage in realistic Q&A sessions where an AI analyzes voice recordings to detect truthfulness. Powered by GPT-4, it evaluates context, logic, tone, and emotion, providing explanations for its judgments. This app is designed for entertainment and fun interactions.

**Highlights:** Voice-based Q&A analysis, AI truth/lie detection, GPT-4 powered analysis, Explanation of judgments, Psychological game for friends, Easy-to-use interface

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

**In-app purchases:** none


## Frequently asked questions

### Is The Master Key System free?

The Master Key System is free to download, with in-app purchases available.

### Is AI Lie Detector. free?

AI Lie Detector. is free to download, with no in-app purchases.

### Do The Master Key System or AI Lie Detector. have ads?

Neither The Master Key System nor AI Lie Detector. shows ads.

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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.*