# SiriusGPS vs Photo Ruler

The clearest difference is in-app purchases: SiriusGPS at none against Photo Ruler's 1. SiriusGPS also leads on device support (3 vs 1) and iOS requirement (14.0 vs 18.0). Photo Ruler's advantage is update cadence (weekly vs every 4 months). On price and ads there is nothing between them.

Both are free to download. Photo Ruler sells 1 in-app purchase, starting at $6.99 per year. SiriusGPS asks for nothing beyond the download.

SiriusGPS ships an update every 4 months, Photo Ruler weekly. The most recent releases landed on November 3, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | SiriusGPS | Photo Ruler |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Weekly** |
| Size | 37 MB | 6 MB |
| Requires iOS | **14.0** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Amine Fellahi](https://appshunter.io/developer/1542759641) | [Ihar Shaduryn](https://appshunter.io/developer/988578285) |

## What reviewers say

### SiriusGPS

[App page](https://appshunter.io/ios/app/siriusgps/id1542759639)

**Features:** macOS Compatibility

**In-app purchases:** none


### Photo Ruler

[App page](https://appshunter.io/ios/app/photo-ruler-measure-objects/id6792457241)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Paper Image Meter Unlimited | $6.99 | per year |


## Frequently asked questions

### Is SiriusGPS free?

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

### Is Photo Ruler free?

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

### Do SiriusGPS or Photo Ruler have ads?

Neither SiriusGPS nor Photo Ruler shows ads.

### Which is updated more often, SiriusGPS or Photo Ruler?

SiriusGPS ships an update every 4 months, and Photo Ruler weekly. Most recently, SiriusGPS was updated on November 3, 2026 and Photo Ruler on October 25, 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.*