# SchoolGuard vs Uncertainty Calculator

The clearest difference is price: SchoolGuard at Free against Uncertainty Calculator's $3.99. SchoolGuard also leads on ratings volume (4 vs 1) and iOS requirement (12.0 vs 17.0). On rating, update cadence, ads and in-app purchases there is nothing between them.

SchoolGuard is free to download; Uncertainty Calculator costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for SchoolGuard against 5.0 for Uncertainty Calculator. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

SchoolGuard ships an update every 6 months, Uncertainty Calculator every 3 months. The most recent releases landed on June 24, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | SchoolGuard | Uncertainty Calculator |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | [5.0 (4 ratings)](https://appshunter.io/ios/app/schoolguard/id768010909/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/uncertainty-calculator/id1170905440/reviews) |
| Number of ratings | **4** | 1 |
| Positive reviews | 71.4% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 3 months** |
| Monetization | **Free** | Paid |
| Size | 58 MB | 1 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Guard911, LLC](https://appshunter.io/developer/862725594) | [Roman Volinsky](https://appshunter.io/developer/977951850) |

## What reviewers say

### SchoolGuard

[App page](https://appshunter.io/ios/app/schoolguard/id768010909)

This app provides K-12 school staff with an immediate panic button for emergencies. Upon activation, it alerts law enforcement, school personnel, and nearby protected schools, while displaying the alert's location.

**Highlights:** One-tap panic button for emergencies, Alerts law enforcement and school staff, Sends location data, Notifies nearby schools, Listed in AT&T FirstNet App Catalog

**In-app purchases:** none


### Uncertainty Calculator

[App page](https://appshunter.io/ios/app/uncertainty-calculator/id1170905440)

This app allows users to perform error propagation calculations for mathematical expressions involving uncertain variables. It supports absolute and relative error inputs, various functions, and trigonometric calculations in degrees or radians. The tool helps ensure accurate reporting of results based on estimated errors.

**Highlights:** Error propagation calculations, Absolute and relative error input, Support for mathematical functions, Trigonometric calculations (degrees/radians), Variable combination in expressions, Significant figure guidance

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

**In-app purchases:** none


## Frequently asked questions

### Is SchoolGuard free?

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

### Is Uncertainty Calculator free?

Uncertainty Calculator costs $3.99, with no in-app purchases.

### Which has better reviews, SchoolGuard or Uncertainty Calculator?

SchoolGuard and Uncertainty Calculator are both rated 5.0 out of 5 on the App Store, from 4 and 1 ratings respectively.

### Do SchoolGuard or Uncertainty Calculator have ads?

Neither SchoolGuard nor Uncertainty Calculator shows ads.

### Which is updated more often, SchoolGuard or Uncertainty Calculator?

SchoolGuard ships an update every 6 months, and Uncertainty Calculator every 3 months. Most recently, SchoolGuard was updated on June 24, 2026 and Uncertainty Calculator on September 14, 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.*