# Heliosy vs GrayZone

The clearest difference is review sentiment: GrayZone at 63% against Heliosy's 0%. GrayZone also leads on update cadence (weekly vs every 4 months) and chart position (#199 vs unranked). Heliosy's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 18.6). On price, ads, in-app purchases and monetization model there is nothing between them.

Heliosy costs $2.99 and GrayZone $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Heliosy ships an update every 4 months, GrayZone weekly. The most recent releases landed on October 6, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Heliosy | GrayZone |
| --- | --- | --- |
| Price | $2.99 | $2.99 |
| Rating | — | **[2.8 (5 ratings)](https://appshunter.io/ios/app/grayzone-light-meter/id6757147623/reviews)** |
| Number of ratings | — | **5** |
| Positive reviews | 0.0% of reviews | **62.5% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Weekly** |
| Monetization | Paid | Paid |
| Best chart rank | — | **#199** |
| Size | 2 MB | 3 MB |
| Requires iOS | **15.0** | 18.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Jean-Christoph KAISER](https://appshunter.io/developer/309381304) | [Massimiliano Schenetti](https://appshunter.io/developer/1864870280) |

## What reviewers say

### Heliosy

[App page](https://appshunter.io/ios/app/heliosy/id980955678)

This app helps you track the sun's position for any day and location. It's useful for photographers planning shoots, real estate agents assessing sunlight, or builders choosing optimal locations for outdoor pools. Visualize sun paths through various displays like live camera, 3D compass, or maps.

**Highlights:** Sun path tracking for current or custom locations, Visualize sun path on live camera, 3D compass sun path display, Sun path on map view, Golden hour and blue hour identification, Twilight times display, Sun path graph

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

**In-app purchases:** none


### GrayZone

[App page](https://appshunter.io/ios/app/grayzone-light-meter/id6757147623)

**Currently charting:** #199 Top Paid · Photo & Video (US App Store)

This app acts as a precise light meter for photographers, allowing you to measure light in specific areas of your scene. It helps achieve consistent exposure and accurate tonal representation, especially in challenging lighting conditions.

**Highlights:** Zone System Mode for tonal analysis, Real SPOT metering for selected areas, Direct exposure control with ISO, shutter speed, and aperture, Live preview with native sensor ratio, UI color inversion option, No ads or data collection

**In-app purchases:** none


## Frequently asked questions

### Is Heliosy free?

Heliosy costs $2.99, with no in-app purchases.

### Is GrayZone free?

GrayZone costs $2.99, with no in-app purchases.

### Do Heliosy or GrayZone have ads?

Neither Heliosy nor GrayZone shows ads.

### Which is updated more often, Heliosy or GrayZone?

Heliosy ships an update every 4 months, and GrayZone weekly. Most recently, Heliosy was updated on October 6, 2026 and GrayZone on October 8, 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.*