# Post Quantum Secure Chat vs DoU

The clearest difference is update cadence: DoU at every 3 days against Post Quantum Secure Chat's every 10 days. Post Quantum Secure Chat's advantage is iOS requirement (13.0 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Post Quantum Secure Chat sells 2 in-app purchases, starting at $4.99 per month and DoU sells 1 in-app purchase, starting at $6.00 per month. Whichever you choose, the download price is not the number that matters.

Post Quantum Secure Chat ships an update every 10 days, DoU every 3 days. The most recent releases landed on October 4, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Post Quantum Secure Chat | DoU |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 10 days | **Every 3 days** |
| Size | 35 MB | 36 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SAYMATIK BILISIM VE TEKNOLOJI ANONIM SIRKETI](https://appshunter.io/developer/1652317997) | [Lemon Cloud Co., Ltd.](https://appshunter.io/developer/1438385187) |

## What reviewers say

### Post Quantum Secure Chat

[App page](https://appshunter.io/ios/app/post-quantum-secure-chat/id6743000247)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Subscription | $4.99 | per month |
| Annual Subscription | $29.99 | per year |


### DoU

[App page](https://appshunter.io/ios/app/dou-personal-messenger/id6758658673)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| DoU Pro 1 (1 Account) | $6.00 | per month |


## Frequently asked questions

### Is Post Quantum Secure Chat free?

Post Quantum Secure Chat is free to download, with in-app purchases available.

### Is DoU free?

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

### Do Post Quantum Secure Chat or DoU have ads?

Neither Post Quantum Secure Chat nor DoU shows ads.

### Which is updated more often, Post Quantum Secure Chat or DoU?

Post Quantum Secure Chat ships an update every 10 days, and DoU every 3 days. Most recently, Post Quantum Secure Chat was updated on October 4, 2026 and DoU on October 18, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*