# Span Calc vs Richardson Alerting

The clearest difference is update cadence: Span Calc at every 10 days against Richardson Alerting's every 2 months. Richardson Alerting's advantage is iOS requirement (12.0 vs 14.2). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Span Calc ships an update every 10 days, Richardson Alerting every 2 months. The most recent releases landed on October 12, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Span Calc | Richardson Alerting |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.9 (15 ratings)](https://appshunter.io/ios/app/span-calc/id380481343/reviews)** | — |
| Number of ratings | **15** | — |
| Positive reviews | 29.6% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 2 months |
| Monetization | Free | — |
| Size | 168 MB | 68 MB |
| Requires iOS | 14.2 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [American Wood Council](https://appshunter.io/developer/380481346) | [Mach Alert Inc.](https://appshunter.io/developer/1472612618) |

## What reviewers say

### Span Calc

[App page](https://appshunter.io/ios/app/span-calc/id380481343)

Calculate maximum horizontal spans for wood joists and rafters using various lumber species and grades. Compares multiple options for common loading conditions based on NDS® standards.

**Highlights:** Calculates joist and rafter spans, Supports all softwood and hardwood lumber, Uses 2021 NDS® for Wood Construction, Compares multiple species and grades, Handles common loading conditions

**Features:** macOS Compatibility

**In-app purchases:** none


### Richardson Alerting

[App page](https://appshunter.io/ios/app/richardson-alerting/id6748761256)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Span Calc free?

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

### Is Richardson Alerting free?

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

### Do Span Calc or Richardson Alerting have ads?

Neither Span Calc nor Richardson Alerting shows ads.

### Which is updated more often, Span Calc or Richardson Alerting?

Span Calc ships an update every 10 days, and Richardson Alerting every 2 months. Most recently, Span Calc was updated on October 12, 2026 and Richardson Alerting on October 19, 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.*