Biorhythms and Critical Days
Sensortronic Lifestyle iPhoneiPadiPod touch
Biorhythms and Critical Days is a free Lifestyle app for iPhone and iPad by Sensortronic. Rated 4.7/5 from 325 ratings. Requires iOS 15.0.
- Rating
- 4.7
- 325 ratings
- Price
- Free
- on the App Store
- Size
- 26 MB
- Age 4+
- Updated
- Oct 7
- 2026 · v5.0.4
Screenshots
About Biorhythms and Critical Days
Calculate your biorhythms and critical days, and check your birth date compatibility with anyone! Biorhythms is a personal biorhythm calculator and chart covering 8 cycles: physical, emotional, intellectual, intuition, fortune, aesthetic, awareness and spiritual, plus an overall daily rating. Create up to 10 user profiles, each with its own color theme and daily reminder. The clean, easy to use interface makes your daily biorhythm check quick and effortless. No account and no sign up: your personal data stays on your device. Features • Elegant, easy to use interface; • 8 biorhythm cycles plus an overall daily rating; • Calculates biorhythms from 2 weeks in the past to 2 months ahead; • Shows each cycle's daily value for the selected period; • Shows each cycle's daily trend (rising / declining); • Daily highlights: a short description and advice for each day; • Birth date compatibility for any two people; • Calculates critical days; • Short, useful advice for each critical day; • 18 color themes to choose from; • Personalized color theme for every user profile; • Personalized daily reminder for every user profile; • Up to 10 user profiles; • Available in 8 languages. Biorhythm theory Biorhythm theory states that our lives move in predictable undulations, driven by cycles that start at birth and run at a fixed pace. The three classic cycles are: • Physical, 23 days; • Emotional, 28 days; • Intellectual, 33 days. Beyond the classic three, the app also charts five extended cycles: intuition (38 days), fortune (21 days), aesthetic (43 days), awareness (48 days) and spiritual (53 days). Critical days A critical day comes when a cycle crosses the zero line, switching from its high phase to its low phase or back. Such days have been described as days of flux and instability. They are not days when an accident will happen, but days when you may be more accident prone. Simply knowing it is a critical day helps you stay on guard and plan around it. Privacy notes • Your personal data (e.g. name and date of birth) is stored locally within your instance of the Biorhythms app only; • If you uninstall the app, your personal data is deleted completely from your device; • We do NOT store your personal data on our premises.
Ratings & reviews
4.7
325 ratings
What’s new
Version 5.0.4 · Updated October 7, 2026
Bug fixes and stability improvements.
App privacy
The developer, Sensortronic, reported these privacy practices to Apple.
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Identifiers: Device ID
- Usage Data: Advertising Data
Data Not Linked to You
The following data, which may be collected but is not linked to your identity, may be used for the following purposes:
- Identifiers: Device ID
- Usage Data: Advertising Data
- Diagnostics: Crash Data, Performance Data
Used for: Third-Party Advertising, App Functionality
Alternatives to Biorhythms and Critical Days
Looking for apps like Biorhythms and Critical Days? Here are 6 similar apps on the App Store. The highest rated is Biorhythm-365 (4.7/5), and 5 of the 6 are free to download.
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Biorhythm-365
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Numerology & Biorhythm
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Biorhythm Calculator Simple
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MyBioCycle
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BiorhythmΩ
4.7
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Biorhythm 365
4.5
| App | Rating | Price | Last updated | Compare |
|---|---|---|---|---|
| Biorhythms and Critical Days | 4.7 / 5 (325 ratings) | Free | October 7, 2026 | |
| Biorhythm-365 | 4.7 / 5 (3,865) | Free | Sep 17, 2026 | Compare |
| Numerology & Biorhythm | 4.7 / 5 (176) | Free | Mar 18, 2026 | Compare |
| Biorhythm Calculator Simple | – | Free | Feb 15, 2024 | Compare |
| MyBioCycle | 4.5 / 5 (2) | Free | Nov 27, 2023 | Compare |
| BiorhythmΩ | 4.7 / 5 (498) | 0.99 USD | Sep 16, 2026 | Compare |
| Biorhythm 365 | 4.5 / 5 (2) | Free | Jun 19, 2026 | Compare |