# ZT vs Детектор Лжи I.S.L

The clearest difference is review sentiment: Детектор Лжи I.S.L at 86% against ZT's 11%. ZT's advantage is price (Free vs $8.99) and rating (4.6 vs 4.0). On in-app purchases, device support and iOS requirement there is nothing between them.

ZT is free to download; Детектор Лжи I.S.L costs $8.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ZT holds the better App Store score, 4.6 against 4.0. That said, the two scores are not equally well evidenced: ZT has 212 ratings behind it against 4, so its average is the more settled of the two. Written reviews complicate that: 11% of ZT's written reviews are positive against 86% of Детектор Лжи I.S.L's, so the app with the better star average is not the one people write more warmly about.

ZT ships an update every 3 weeks, Детектор Лжи I.S.L every 5 months. The most recent releases landed on September 28, 2026 and June 10, 2026 respectively.

## The numbers

| Metric | ZT | Детектор Лжи I.S.L |
| --- | --- | --- |
| Price | **Free** | $8.99 |
| Rating | **[4.6 (212 ratings)](https://appshunter.io/ios/app/zt/id1214656147/reviews)** | [4.0 (4 ratings)](https://appshunter.io/ios/app/isl/id1611247031/reviews) |
| Number of ratings | **212** | 4 |
| Positive reviews | 11.1% of reviews | **85.7% of reviews** |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 3 weeks** | Every 5 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 121 MB | 81 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 9+ |
| Developer | [ZTK, OOO](https://appshunter.io/developer/1577726159) | [ALGORITHM LLC apps](https://appshunter.io/developer/1459520987) |

## What reviewers say

### ZT

[App page](https://appshunter.io/ios/app/zt/id1214656147)

Connect with incarcerated individuals through a comprehensive mobile service. Send letters, photos, make audio/video calls, and transfer funds. Offers entertainment options like puzzles and games to enrich communication.

**Highlights:** Send electronic letters and photos, Make audio and video calls, Transfer money to inmate accounts, Add puzzles and games to letters, Instant printing at correctional facilities

**Features:** Vision Pro support

**In-app purchases:** none


### Детектор Лжи I.S.L

[App page](https://appshunter.io/ios/app/isl/id1611247031)

This app uses unique technologies and physiological data to estimate the likelihood of deception. It is intended for entertainment purposes only and is not a professional lie detector. Users must obtain consent before testing.

**Highlights:** Estimates deception using physiological data, Developed with professional psychologists, Entertainment purposes only, Requires user consent for testing, Not a professional polygraph

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ZT free?

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

### Is Детектор Лжи I.S.L free?

Детектор Лжи I.S.L costs $8.99, with no in-app purchases.

### Which has better reviews, ZT or Детектор Лжи I.S.L?

ZT is rated higher. ZT averages 4.6 out of 5 from 212 ratings, while Детектор Лжи I.S.L averages 4.0 from 4 ratings.

### Do ZT or Детектор Лжи I.S.L have ads?

Детектор Лжи I.S.L shows ads; ZT does not.

### Which is updated more often, ZT or Детектор Лжи I.S.L?

ZT ships an update every 3 weeks, and Детектор Лжи I.S.L every 5 months. Most recently, ZT was updated on September 28, 2026 and Детектор Лжи I.S.L on June 10, 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.*