# Light Meter LM vs MobAlerm

The clearest difference is price: Light Meter LM at Free against MobAlerm's $0.49. MobAlerm's advantage is in-app purchases (none vs 3) and update cadence (every 10 days vs monthly). On ads and device support there is nothing between them.

Light Meter LM is free to download; MobAlerm costs $0.49 up front. Light Meter LM sells 3 in-app purchases, starting at $3.49 per month. MobAlerm asks for nothing beyond the download.

Light Meter LM ships an update monthly, MobAlerm every 10 days. The most recent releases landed on October 25, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Light Meter LM | MobAlerm |
| --- | --- | --- |
| Price | **Free** | $0.49 |
| Rating | **[4.5 (2.6K ratings)](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761/reviews)** | — |
| Number of ratings | **2.6K** | — |
| Positive reviews | 40.4% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | **Every 10 days** |
| Monetization | Free with in-app purchases | — |
| Size | 22 MB | 1 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPod, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Lightray Innovation GmbH](https://appshunter.io/developer/1031383431) | [Kengo Tate](https://appshunter.io/developer/1458012620) |

## What reviewers say

### Light Meter LM

[App page](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761)

Transform your smartphone into a professional light meter. Measure illuminance and color temperature with scientifically validated accuracy, trusted by professionals. Requires a simple diffuser for precise readings.

**Highlights:** Measure illuminance (lux/foot-candle), Measure color temperature (Kelvin), Industry-leading accuracy, Pre-calibrated for your device, Low light sensitivity, Save peak reading, Custom calibration option

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Continuous Charging | $3.49 | per month |
| Single Charge | $0.99 | one-time |
| Unlimited Battery | $19.99 | one-time |

**What reviewers like**

- 👍 Great app
- 👍 Accurate measurements
- 👍 Easy to use
- 👍 Helpful customer service
- 👍 Useful for science/research

**What reviewers complain about**

- 🐛 Requires diffuser for accurate readings
- 💰 Expensive for a light meter app
- 🔋 Battery/trial period issues
- 🔍 Inconsistent/inaccurate readings
- 🙄 Misleading/deceptive marketing

**Reported bugs**

- Diffuser not recognized even when used
- App locks up/crashes
- Constant diffuser pop-up interruptions

**Requested features**

- Ability to use rear camera
- More flexible diffuser options
- Improved accuracy without diffuser


### MobAlerm

[App page](https://appshunter.io/ios/app/mobalerm/id6737408995)

**In-app purchases:** none


## Frequently asked questions

### Is Light Meter LM free?

Light Meter LM is free to download, with in-app purchases available.

### Is MobAlerm free?

MobAlerm costs $0.49, with no in-app purchases.

### Do Light Meter LM or MobAlerm have ads?

Neither Light Meter LM nor MobAlerm shows ads.

### Which is updated more often, Light Meter LM or MobAlerm?

Light Meter LM ships an update monthly, and MobAlerm every 10 days. Most recently, Light Meter LM was updated on October 25, 2026 and MobAlerm on October 11, 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.*