# Ruler & Digital Caliper vs DIAMETRO

The clearest difference is in-app purchases: DIAMETRO at none against Ruler & Digital Caliper's 1. Ruler & Digital Caliper's advantage is update cadence (every 3 days vs every 2 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Ruler & Digital Caliper sells 1 one-off in-app purchase. DIAMETRO asks for nothing beyond the download.

Ruler & Digital Caliper ships an update every 3 days, DIAMETRO every 2 weeks. The most recent releases landed on October 25, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | Ruler & Digital Caliper | DIAMETRO |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 2 weeks |
| Size | 5 MB | 4 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Yurii Koshkin](https://appshunter.io/developer/1873601061) | [ALEXANDRU TEODOR TRANDAFIR](https://appshunter.io/developer/6810555118) |

## What reviewers say

### Ruler & Digital Caliper

[App page](https://appshunter.io/ios/app/ruler-and-digital-caliper/id6806950163)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Access | $9.99 | one-time |


### DIAMETRO

[App page](https://appshunter.io/ios/app/diametro-ring-sizer/id6810555116)

**In-app purchases:** none


## Frequently asked questions

### Is Ruler & Digital Caliper free?

Ruler & Digital Caliper is free to download, with in-app purchases available.

### Is DIAMETRO free?

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

### Do Ruler & Digital Caliper or DIAMETRO have ads?

Neither Ruler & Digital Caliper nor DIAMETRO shows ads.

### Which is updated more often, Ruler & Digital Caliper or DIAMETRO?

Ruler & Digital Caliper ships an update every 3 days, and DIAMETRO every 2 weeks. Most recently, Ruler & Digital Caliper was updated on October 25, 2026 and DIAMETRO on October 21, 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.*