# Ruler & Digital Caliper vs ConvertPro

The clearest difference is update cadence: Ruler & Digital Caliper at every 4 days against ConvertPro's monthly. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Ruler & Digital Caliper sells 1 one-off in-app purchase and ConvertPro sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Ruler & Digital Caliper ships an update every 4 days, ConvertPro monthly. Both last shipped on October 31, 2026.

## The numbers

| Metric | Ruler & Digital Caliper | ConvertPro |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Monthly |
| Size | 6 MB | 5 MB |
| Requires iOS | **17.0** | 18.0 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Yurii Koshkin](https://appshunter.io/developer/1873601061) | [Ademola Mayowa Olatunji](https://appshunter.io/developer/1862678370) |

## 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 |


### ConvertPro

[App page](https://appshunter.io/ios/app/convertpro-unit-converter/id6809904618)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ConvertPro Pro | $4.99 | one-time |


## Frequently asked questions

### Is Ruler & Digital Caliper free?

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

### Is ConvertPro free?

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

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

Neither Ruler & Digital Caliper nor ConvertPro shows ads.

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

Ruler & Digital Caliper ships an update every 4 days, and ConvertPro monthly. Most recently, Ruler & Digital Caliper was updated on October 31, 2026 and ConvertPro on October 31, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*