# 531 Strength vs Rhythm LightScore

The clearest difference is in-app purchases: Rhythm LightScore at none against 531 Strength's 4. Rhythm LightScore also leads on ads (none vs shown) and update cadence (every 4 days vs every 2 months). 531 Strength's advantage is ratings volume (12K vs 5). On price, rating, review sentiment and device support there is nothing between them.

Both are free to download. 531 Strength sells 4 one-off in-app purchases. Rhythm LightScore asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.9 for 531 Strength against 5.0 for Rhythm LightScore. That said, the two scores are not equally well evidenced: 531 Strength has 12K ratings behind it against 5, so its average is the more settled of the two. Written reviews are what separate them: 94% of 531 Strength's written reviews are positive against 100% of Rhythm LightScore's.

531 Strength ships an update every 2 months, Rhythm LightScore every 4 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | 531 Strength | Rhythm LightScore |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.9 (12K ratings)](https://appshunter.io/ios/app/531-strength/id1062989244/reviews) | **[5.0 (5 ratings)](https://appshunter.io/ios/app/rhythm-lightscore/id6799837500/reviews)** |
| Number of ratings | **12K** | 5 |
| Positive reviews | 94.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Every 4 days** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 26 MB | 26 MB |
| Requires iOS | 18.0 | 18.0 |
| Devices | iPhone, iPad | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Henrik Jachobsen](https://appshunter.io/developer/497731838) | [Rhythm Innovations, Inc.](https://appshunter.io/developer/6799837502) |

## What reviewers say

### 531 Strength

[App page](https://appshunter.io/ios/app/531-strength/id1062989244)

This app simplifies tracking your progress on the 5/3/1 strength training program. It calculates and displays weights, reps, and sets based on your one-rep max, allowing you to easily plan and execute your workouts. Rounding options help match available gym plates.

**Highlights:** Calculate 5/3/1 weights, Track 1RM for exercises, View cycle step weights, Round weights to available plates, Full overview of weights, reps, sets

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Additional exercises | $1.99 | one-time |
| Adjustable set | $1.99 | one-time |
| Plate calculator | $1.99 | one-time |
| Progress log | $6.99 | one-time |

**What reviewers like**

- 🚀 Simple and efficient
- 👍 Intuitive interface
- 💪 Helps with strength gains
- 🔧 Customizable features
- ⏱️ Convenient timer

**What reviewers complain about**

- 🔢 Inaccurate percentage calculations
- 🗓️ Lack of ability to plan future workouts
- 📋 Limited exercise tracking
- 💰 Paid features not worth the cost

**Reported bugs**

- Rest timer stops when app is backgrounded
- Plate calculator not flexible enough

**Requested features**

- Ability to adjust training max separately from 1RM
- Option to track rep PRs and estimated 1RM
- Accessory exercise tracking and planning
- Sync progress across devices


### Rhythm LightScore

[App page](https://appshunter.io/ios/app/rhythm-lightscore/id6799837500)

This app provides a daily "LightScore" based on your exposure to daylight, its consistency, and your pre-bedtime phone use. It offers insights into your light habits and suggests improvements for better well-being.

**Highlights:** Daily LightScore out of 100, Measures Light Time, Consistency, and Dark Time, Integrates with Apple Watch Health data, Uses phone camera as a light meter, Visualizes daily progress with Sol character, Sunset photo capture and sharing

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is 531 Strength free?

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

### Is Rhythm LightScore free?

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

### Which has better reviews, 531 Strength or Rhythm LightScore?

Rhythm LightScore is rated higher. 531 Strength averages 4.9 out of 5 from 12K ratings, while Rhythm LightScore averages 5.0 from 5 ratings.

### Do 531 Strength or Rhythm LightScore have ads?

531 Strength shows ads; Rhythm LightScore does not.

### Which is updated more often, 531 Strength or Rhythm LightScore?

531 Strength ships an update every 2 months, and Rhythm LightScore every 4 days. Most recently, 531 Strength was updated on October 24, 2026 and Rhythm LightScore 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.*