# Standard Deviation Calc vs GPD

The clearest difference is review sentiment: GPD at 100% against Standard Deviation Calc's 0%. GPD also leads on in-app purchases (none vs 1) and update cadence (every 2 months vs every 5 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Standard Deviation Calc sells 1 one-off in-app purchase. GPD asks for nothing beyond the download.

Standard Deviation Calc ships an update every 5 months, GPD every 2 months. The most recent releases landed on October 8, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Standard Deviation Calc | GPD |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.7 (11 ratings)](https://appshunter.io/ios/app/standard-deviation-calc-sd/id1497525733/reviews)** | — |
| Number of ratings | **11** | — |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 2 MB | 20 MB |
| Requires iOS | **14.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Phan Nhat Đang](https://appshunter.io/developer/1437390098) | [Charles Steinmetz](https://appshunter.io/developer/1514567876) |

## What reviewers say

### Standard Deviation Calc

[App page](https://appshunter.io/ios/app/standard-deviation-calc-sd/id1497525733)

Calculate standard deviation for sample or population data. Input numerical values to find standard deviation, count, sum, mean, variance, and more. Get quick statistical insights with this easy-to-use tool.

**Highlights:** Calculate standard deviation, Sample or population data, Compute mean and variance, Count numerical values, Sum of numbers, List of differences

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove ads | $1.99 | one-time |


### GPD

[App page](https://appshunter.io/ios/app/gpd/id1514567877)

This app helps farmers assess planting uniformity by measuring seed spacing. It calculates the Coefficient of Variation (CV%) and analyzes distribution regularity, identifying acceptable spacing, doubles, and skips to improve crop yield.

**Highlights:** Measures seed spacing uniformity, Calculates Coefficient of Variation (CV%), Analyzes distribution regularity (acceptable, doubles, skips), Identifies causes of planting errors, Aids in improving plantability

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

**In-app purchases:** none


## Frequently asked questions

### Is Standard Deviation Calc free?

Standard Deviation Calc is free to download, with in-app purchases available.

### Is GPD free?

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

### Do Standard Deviation Calc or GPD have ads?

Neither Standard Deviation Calc nor GPD shows ads.

### Which is updated more often, Standard Deviation Calc or GPD?

Standard Deviation Calc ships an update every 5 months, and GPD every 2 months. Most recently, Standard Deviation Calc was updated on October 8, 2026 and GPD on October 5, 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.*