# ISO Fits vs Design Materials

The clearest difference is review sentiment: ISO Fits at 95% against Design Materials's 33%. ISO Fits also leads on ratings volume (6 vs 2) and iOS requirement (15.6 vs 18.6). Design Materials's advantage is rating (4.5 vs 4.2). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. ISO Fits sells 1 one-off in-app purchase and Design Materials sells 3 in-app purchases, starting at $7.99 per month. Whichever you choose, the download price is not the number that matters.

Design Materials holds the better App Store score, 4.5 against 4.2. Both are backed by a comparable volume of ratings — 6 and 2 respectively. Written reviews complicate that: 95% of ISO Fits's written reviews are positive against 33% of Design Materials's, so the app with the better star average is not the one people write more warmly about.

ISO Fits ships an update every 5 months, Design Materials every 3 months. The most recent releases landed on September 12, 2026 and July 23, 2026 respectively.

## The numbers

| Metric | ISO Fits | Design Materials |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.2 (6 ratings)](https://appshunter.io/ios/app/iso-fits/id396863755/reviews) | **[4.5 (2 ratings)](https://appshunter.io/ios/app/design-materials/id975764691/reviews)** |
| Number of ratings | **6** | 2 |
| Positive reviews | **94.6% of reviews** | 33.3% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 months** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 66 MB | 28 MB |
| Requires iOS | **15.6** | 18.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) | [Chrystian Enriquez](https://appshunter.io/developer/428286625) |

## What reviewers say

### ISO Fits

[App page](https://appshunter.io/ios/app/iso-fits/id396863755)

Calculate ISO fits and tolerances for shafts and bores. Supports metric and inch units, displays detailed fit definitions, and includes visual charts and educational videos.

**Highlights:** ISO fits calculation, Tolerance class display, Metric/inch unit switching, Tolerance charts, Updated YouTube videos

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Version with complete ISO286 Standard | $1.99 | one-time |


### Design Materials

[App page](https://appshunter.io/ios/app/design-materials/id975764691)

This app serves as an offline reference guide for various design materials, including polymers and metals. It allows users to manage their own material data, view 3D models, and capture objects with their device's camera. Ideal for professionals and hobbyists involved in product design and 3D printing.

**Highlights:** Offline material reference guide, Custom material and resin management, 3D model viewer and import/export, Object capture via device camera, Favorites and notes section, Cross-device compatibility (iOS, macOS)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Bronze member | $7.99 | per month |
| Silver member | $17.99 | per 3 months |
| Gold member | $49.99 | per year |


## Frequently asked questions

### Is ISO Fits free?

ISO Fits is free to download, with in-app purchases available.

### Is Design Materials free?

Design Materials is free to download, with in-app purchases available.

### Which has better reviews, ISO Fits or Design Materials?

Design Materials is rated higher. ISO Fits averages 4.2 out of 5 from 6 ratings, while Design Materials averages 4.5 from 2 ratings.

### Do ISO Fits or Design Materials have ads?

Neither ISO Fits nor Design Materials shows ads.

### Which is updated more often, ISO Fits or Design Materials?

ISO Fits ships an update every 5 months, and Design Materials every 3 months. Most recently, ISO Fits was updated on September 12, 2026 and Design Materials on July 23, 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.*