# Biorhythm Alertness vs System

The clearest difference is rating: Biorhythm Alertness at 2.0 against System's 1.0. Biorhythm Alertness also leads on ratings volume (4 vs 1) and device support (3 vs 1). System's advantage is in-app purchases (none vs 1) and update cadence (every 8 days vs every 5 weeks). On price, ads and monetization model there is nothing between them.

Both are free to download. Biorhythm Alertness sells 1 one-off in-app purchase. System asks for nothing beyond the download.

Biorhythm Alertness holds the better App Store score, 2.0 against 1.0. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

Biorhythm Alertness ships an update every 5 weeks, System every 8 days. The most recent releases landed on October 21, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Biorhythm Alertness | System |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.0 (4 ratings)](https://appshunter.io/ios/app/biorhythm-alertness/id1351359147/reviews)** | [1.0 (1 ratings)](https://appshunter.io/ios/app/system-understand-yourself/id6480427972/reviews) |
| Number of ratings | **4** | 1 |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 8 days** |
| Monetization | Free | Free |
| Size | 5 MB | 6 MB |
| Requires iOS | **14.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Bodnar Marin](https://appshunter.io/developer/1344307163) | [Matteo Dada](https://appshunter.io/developer/1551807661) |

## What reviewers say

### Biorhythm Alertness

[App page](https://appshunter.io/ios/app/biorhythm-alertness/id1351359147)

This app tracks your physical, emotional, intellectual, and intuitive biological cycles. It provides visual graphs of these rhythms and notifies you of critical days when your vulnerability is highest. Easily manage multiple user profiles for family and friends.

**Highlights:** Multi-user profile support, Visualizations of physical, emotional, intellectual, and intuitive rhythms, Critical day notifications, Toggle display for individual rhythm curves, Simple registration with name and birthdate, User-friendly interface

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Biorhythm Alerter | $0.99 | one-time |


### System

[App page](https://appshunter.io/ios/app/system-understand-yourself/id6480427972)

This app helps you discover hidden patterns by connecting your daily behaviors and feelings. It provides a personal journal, an insights dashboard, and mapping tools to understand how actions influence emotions and vice versa, fostering self-awareness and data-driven growth.

**Highlights:** Personal journal for recording moments and feelings, Insights dashboard to visualize recurring behaviors and emotions, Behavior-emotion mapping to understand action-feeling connections, Emotion-action insights to see how feelings influence choices, Mindfulness encouragement with simple daily tracking, Data-driven growth through personal experience analysis

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Biorhythm Alertness free?

Biorhythm Alertness is free to download, with in-app purchases available.

### Is System free?

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

### Which has better reviews, Biorhythm Alertness or System?

Biorhythm Alertness is rated higher. Biorhythm Alertness averages 2.0 out of 5 from 4 ratings, while System averages 1.0 from 1 ratings.

### Do Biorhythm Alertness or System have ads?

Neither Biorhythm Alertness nor System shows ads.

### Which is updated more often, Biorhythm Alertness or System?

Biorhythm Alertness ships an update every 5 weeks, and System every 8 days. Most recently, Biorhythm Alertness was updated on October 21, 2026 and System on October 15, 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.*