# Theta vs Luminosys

The clearest difference is rating: Theta at 5.0 against Luminosys's 4.3. Theta also leads on ads (none vs shown) and update cadence (monthly vs every 19 months). Luminosys's advantage is ratings volume (10 vs 1). On price and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Theta holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: Luminosys has 10 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Theta's written reviews are positive against 75% of Luminosys's.

Theta ships an update monthly, Luminosys every 19 months. The most recent releases landed on October 4, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Theta | Luminosys |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/theta-meter-light/id1077931723/reviews)** | [4.3 (10 ratings)](https://appshunter.io/ios/app/luminosys-light-meter/id6476405389/reviews) |
| Number of ratings | 1 | **10** |
| Positive reviews | **100.0% of reviews** | 75.0% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Monthly** | Every 19 months |
| Monetization | **Free** | Ad-supported |
| Size | 13 MB | 3 MB |
| Requires iOS | **11.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Mikhail Fedorov](https://appshunter.io/developer/714735606) | [Melissa Zwick](https://appshunter.io/developer/1616726350) |

## What reviewers say

### Theta

[App page](https://appshunter.io/ios/app/theta-meter-light/id1077931723)

This application connects to specialized devices to measure and display galvanic skin response. It utilizes Wi-Fi and Bluetooth 4.0BLE to collect data on skin conductance, providing insights into physiological responses.

**Highlights:** Galvanic skin response measurement, Wi-Fi connectivity, Bluetooth 4.0BLE connection, Skin conductance data display, Physiological response tracking

**In-app purchases:** none


### Luminosys

[App page](https://appshunter.io/ios/app/luminosys-light-meter/id6476405389)

Accurately measure ambient light levels in Lux or Foot Candles using your phone's camera. This tool is ideal for photography, comparing light sources, or indoor gardening. It's designed for ease of use and provides precise readings.

**Highlights:** Measures light in Lux, Measures light in Foot Candles (FC), Uses phone camera for accuracy, Easy to use interface, Suitable for photography, Useful for indoor gardening

**In-app purchases:** none


## Frequently asked questions

### Is Theta free?

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

### Is Luminosys free?

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

### Which has better reviews, Theta or Luminosys?

Theta is rated higher. Theta averages 5.0 out of 5 from 1 ratings, while Luminosys averages 4.3 from 10 ratings.

### Do Theta or Luminosys have ads?

Luminosys shows ads; Theta does not.

### Which is updated more often, Theta or Luminosys?

Theta ships an update monthly, and Luminosys every 19 months. Most recently, Theta was updated on October 4, 2026 and Luminosys 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.*