# Ring Sizer vs OneOpen

The clearest difference is ads: OneOpen at none against Ring Sizer's shown. OneOpen also leads on update cadence (every 3 days vs fortnightly). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Ring Sizer sells 2 in-app purchases, starting at $4.99 per 7 days and OneOpen sells 2 in-app purchases, starting at $0.99 per year. Whichever you choose, the download price is not the number that matters.

Ring Sizer ships an update fortnightly, OneOpen every 3 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | Ring Sizer | OneOpen |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Fortnightly | **Every 3 days** |
| Size | 62 MB | 73 MB |
| Requires iOS | **16.6** | 17.0 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Mastertex Fab](https://appshunter.io/developer/1857166298) | [Freedom Dimension (shenzhen) Technology Co., Ltd](https://appshunter.io/developer/6776064465) |

## What reviewers say

### Ring Sizer

[App page](https://appshunter.io/ios/app/ring-sizer-finger-size/id6788002855)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| MeasureRing One Week | $4.99 | per 7 days |
| MeasureRing One Year | $19.99 | per year |


### OneOpen

[App page](https://appshunter.io/ios/app/oneopen-file-viewer/id6792251542)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Advanced Access Annual | $0.99 | per year |
| Advanced Access Lifetime | $2.99 | one-time |


## Frequently asked questions

### Is Ring Sizer free?

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

### Is OneOpen free?

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

### Do Ring Sizer or OneOpen have ads?

Ring Sizer shows ads; OneOpen does not.

### Which is updated more often, Ring Sizer or OneOpen?

Ring Sizer ships an update fortnightly, and OneOpen every 3 days. Most recently, Ring Sizer was updated on October 24, 2026 and OneOpen on October 24, 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.*