# SEM vs Dead Man Switch

The clearest difference is in-app purchases: SEM at none against Dead Man Switch's 1. Dead Man Switch's advantage is update cadence (every 4 days vs every 2 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Dead Man Switch sells 1 in-app purchase, starting at $4.99 per year. SEM asks for nothing beyond the download.

SEM ships an update every 2 weeks, Dead Man Switch every 4 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | SEM | Dead Man Switch |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.4 (11 ratings)](https://appshunter.io/ios/app/sem-meter/id6468902139/reviews)** | — |
| Number of ratings | **11** | — |
| Positive reviews | 37.5% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 4 days** |
| Monetization | Free | — |
| Size | 31 MB | 44 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Hangzhou Dashi Wisdom Technology Co., Ltd.](https://appshunter.io/developer/1822219570) | [Nam Nguyen](https://appshunter.io/developer/1727360199) |

## What reviewers say

### SEM

[App page](https://appshunter.io/ios/app/sem-meter/id6468902139)

This utility app monitors your household power consumption in real-time, providing historical data and comparisons to help you save on electricity bills. It supports managing multiple devices and customizing electricity fee calculations.

**Highlights:** Real-time power usage monitoring, Historical energy use tracking, Second-to-second, day-to-day, week-to-week, month-to-month, and year-to-year comparisons, Electricity fee gradient calculation, Customizable fee templates, Multiple device management

**In-app purchases:** none


### Dead Man Switch

[App page](https://appshunter.io/ios/app/dead-man-switch-safety-alert/id6809491387)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Annual Access | $4.99 | per year |


## Frequently asked questions

### Is SEM free?

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

### Is Dead Man Switch free?

Dead Man Switch is free to download, with in-app purchases available.

### Do SEM or Dead Man Switch have ads?

Neither SEM nor Dead Man Switch shows ads.

### Which is updated more often, SEM or Dead Man Switch?

SEM ships an update every 2 weeks, and Dead Man Switch every 4 days. Most recently, SEM was updated on October 24, 2026 and Dead Man Switch on October 24, 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.*