# TCT OTP vs One

The clearest difference is in-app purchases: TCT OTP at none against One's 4. TCT OTP also leads on device support (3 vs 1) and iOS requirement (11.0 vs 17.0). On price and ads there is nothing between them.

Both are free to download. One sells 4 one-off in-app purchases. TCT OTP asks for nothing beyond the download.

## The numbers

| Metric | TCT OTP | One |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | — |
| Size | 29 MB | 35 MB |
| Requires iOS | **11.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 12+ |
| Developer | [IT Department, General Department of Taxation of Viet Nam](https://appshunter.io/developer/1589750684) | [PWZ COM CORP](https://appshunter.io/developer/1883572739) |

## What reviewers say

### TCT OTP

[App page](https://appshunter.io/ios/app/tct-otp/id1636407223)

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

**In-app purchases:** none


### One

[App page](https://appshunter.io/ios/app/one-ai/id6761099079)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Starter | $9.90 | one-time |
| Basic | $29.90 | one-time |
| Plus | $49.90 | one-time |
| Professional | $99.90 | one-time |


## Frequently asked questions

### Is TCT OTP free?

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

### Is One free?

One is free to download, with in-app purchases available.

### Do TCT OTP or One have ads?

Neither TCT OTP nor One 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.*