# NORTON iGRIND vs SumiTool Calculator

The clearest difference is rating: NORTON iGRIND at 5.0 against SumiTool Calculator's 1.0. NORTON iGRIND also leads on ads (none vs shown) and update cadence (monthly vs every 8 months). SumiTool Calculator's advantage is iOS requirement (10.0 vs 14.0). On price, 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.

NORTON iGRIND holds the better App Store score, 5.0 against 1.0. That said, the two scores are not equally well evidenced: NORTON iGRIND has 5 ratings behind it against 1, so its average is the more settled of the two.

NORTON iGRIND ships an update monthly, SumiTool Calculator every 8 months. The most recent releases landed on October 14, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | NORTON iGRIND | SumiTool Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (5 ratings)](https://appshunter.io/ios/app/norton-igrind/id550147080/reviews)** | [1.0 (1 ratings)](https://appshunter.io/ios/app/sumitool-calculator/id1473928608/reviews) |
| Number of ratings | **5** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Monthly** | Every 8 months |
| Monetization | **Free** | Ad-supported |
| Size | 20 MB | 51 MB |
| Requires iOS | 14.0 | **10.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Saint-Gobain](https://appshunter.io/developer/543924473) | [SUMITOMO ELECTRIC INDUSTRIES,LTD.](https://appshunter.io/developer/1102241900) |

## What reviewers say

### NORTON iGRIND

[App page](https://appshunter.io/ios/app/norton-igrind/id550147080)

This app provides essential calculators and conversion tools for grinding processes. It helps users determine starting parameters for wheel truing, optimize coolant delivery, and convert wheel speeds for safe operation.

**Highlights:** Grinding wheel truing parameter calculator, Coolant delivery setup optimization, Wheel speed conversion (RPM, SFPM, M/Sec), Safe grinding operation tools, Expert-created calculations

**Features:** macOS Compatibility

**In-app purchases:** none


### SumiTool Calculator

[App page](https://appshunter.io/ios/app/sumitool-calculator/id1473928608)

This app simplifies complex machining calculations for turning, milling, and drilling. Users select an operation, input figures, and receive automatic results. It allows saving calculations for logs and comparing two results simultaneously.

**Highlights:** Automatic calculation for turning, milling, drilling, Customizable item display order, Save calculation results, Log viewing, Side-by-side result comparison

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is NORTON iGRIND free?

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

### Is SumiTool Calculator free?

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

### Which has better reviews, NORTON iGRIND or SumiTool Calculator?

NORTON iGRIND is rated higher. NORTON iGRIND averages 5.0 out of 5 from 5 ratings, while SumiTool Calculator averages 1.0 from 1 ratings.

### Do NORTON iGRIND or SumiTool Calculator have ads?

SumiTool Calculator shows ads; NORTON iGRIND does not.

### Which is updated more often, NORTON iGRIND or SumiTool Calculator?

NORTON iGRIND ships an update monthly, and SumiTool Calculator every 8 months. Most recently, NORTON iGRIND was updated on October 14, 2026 and SumiTool Calculator on October 6, 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.*