# 21 vs Hidden Device Radar

The clearest difference is in-app purchases: 21 at none against Hidden Device Radar's 1. On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Hidden Device Radar sells 1 one-off in-app purchase. 21 asks for nothing beyond the download.

## The numbers

| Metric | 21 | Hidden Device Radar |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hidden-device-radar/id6760244313/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | — | Every 2 weeks |
| Monetization | — | Free with in-app purchases |
| Size | 11 MB | 8 MB |
| Requires iOS | 18.4 | **17.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Najib El guertit](https://appshunter.io/developer/1816291075) | [Aurem Digital llc](https://appshunter.io/developer/1882003730) |

## What reviewers say

### 21

[App page](https://appshunter.io/ios/app/21-card/id6746346266)

**Features:** macOS Compatibility

**In-app purchases:** none


### Hidden Device Radar

[App page](https://appshunter.io/ios/app/hidden-device-radar/id6760244313)

Detect hidden cameras, trackers, and smart devices using Bluetooth, Wi-Fi, and NFC signals. Get real-time threat scoring and a proximity graph to locate suspicious devices. Protect your privacy by scanning hotel rooms, rentals, or your home.

**Highlights:** Bluetooth device detection, Wi-Fi/local network scanning, Real-time threat scoring, Signal Strength Finder (Pro), Detection history, On-device processing

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hidden Device Radar | $4.99 | one-time |


## Frequently asked questions

### Is 21 free?

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

### Is Hidden Device Radar free?

Hidden Device Radar is free to download, with in-app purchases available.

### Do 21 or Hidden Device Radar have ads?

Neither 21 nor Hidden Device Radar 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.*