# Powerful Silent Timer vs Dual Screen Sync

The clearest difference is price: Dual Screen Sync at Free against Powerful Silent Timer's $0.99. Powerful Silent Timer's advantage is iOS requirement (7.0 vs 16.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Dual Screen Sync is free to download; Powerful Silent Timer costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Powerful Silent Timer ships an update every 2 weeks, Dual Screen Sync every 3 weeks. The most recent releases landed on November 1, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Powerful Silent Timer | Dual Screen Sync |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/powerful-silent-timer-vibration-alarm-for-library-train-etc/id873008064/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 62.1% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | Paid | — |
| Size | 3 MB | 1 MB |
| Requires iOS | **7.0** | 16.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [Sho Kurozumi](https://appshunter.io/developer/796307880) | [Insik Shin](https://appshunter.io/developer/1740272742) |

## What reviewers say

### Powerful Silent Timer

[App page](https://appshunter.io/ios/app/powerful-silent-timer-vibration-alarm-for-library-train-etc/id873008064)

This app provides a silent vibration alarm to prevent missing your stop on public transport or to stay focused during study. It offers customizable vibration intensity and a software lock to prevent accidental cancellation.

**Highlights:** Silent vibration alarm, Customizable vibration intensity (Silent, Normal, Powerful), Software lock to prevent accidental cancellation, Timer status check during lock, Ideal for commuting and study

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

**In-app purchases:** none


### Dual Screen Sync

[App page](https://appshunter.io/ios/app/dual-screen-sync/id6737029339)

**In-app purchases:** none


## Frequently asked questions

### Is Powerful Silent Timer free?

Powerful Silent Timer costs $0.99, with no in-app purchases.

### Is Dual Screen Sync free?

Dual Screen Sync is free to download, with no in-app purchases.

### Do Powerful Silent Timer or Dual Screen Sync have ads?

Neither Powerful Silent Timer nor Dual Screen Sync shows ads.

### Which is updated more often, Powerful Silent Timer or Dual Screen Sync?

Powerful Silent Timer ships an update every 2 weeks, and Dual Screen Sync every 3 weeks. Most recently, Powerful Silent Timer was updated on November 1, 2026 and Dual Screen Sync on October 25, 2026.

---

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