# E Sentry Systems vs Carpenter Tools

The clearest difference is in-app purchases: E Sentry Systems at none against Carpenter Tools's 1. E Sentry Systems also leads on update cadence (every 3 weeks vs every 6 weeks) and iOS requirement (16.0 vs 18.0). On price, ads and device support there is nothing between them.

Both are free to download. Carpenter Tools sells 1 one-off in-app purchase. E Sentry Systems asks for nothing beyond the download.

E Sentry Systems ships an update every 3 weeks, Carpenter Tools every 6 weeks. The most recent releases landed on October 13, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | E Sentry Systems | Carpenter Tools |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.9 (8 ratings)](https://appshunter.io/ios/app/carpenter-tools-calculator/id6757513389/reviews)** |
| Number of ratings | — | **8** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 6 weeks |
| Monetization | — | Free with in-app purchases |
| Size | 54 MB | 3 MB |
| Requires iOS | **16.0** | 18.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [IRISS Inc](https://appshunter.io/developer/1245323320) | [Sergii Nesterenko](https://appshunter.io/developer/1686841405) |

## What reviewers say

### E Sentry Systems

[App page](https://appshunter.io/ios/app/e-sentry-systems/id6444192723)

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

**In-app purchases:** none


### Carpenter Tools

[App page](https://appshunter.io/ios/app/carpenter-tools-calculator/id6757513389)

This app simplifies carpentry calculations for framing, roofing, stairs, and more. Quickly get accurate measurements and material counts without complex formulas or spreadsheets. Ideal for on-site work, shop use, or estimating.

**Highlights:** Framing calculations, Rafter and roof calculations, Stair rise and run, Material count estimation, Imperial and metric units, Helpful diagrams, Optional cost fields

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Upgrade | $12.99 | one-time |


## Frequently asked questions

### Is E Sentry Systems free?

E Sentry Systems is free to download, with no in-app purchases.

### Is Carpenter Tools free?

Carpenter Tools is free to download, with in-app purchases available.

### Do E Sentry Systems or Carpenter Tools have ads?

Neither E Sentry Systems nor Carpenter Tools shows ads.

### Which is updated more often, E Sentry Systems or Carpenter Tools?

E Sentry Systems ships an update every 3 weeks, and Carpenter Tools every 6 weeks. Most recently, E Sentry Systems was updated on October 13, 2026 and Carpenter Tools on October 17, 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.*