MyCircadianApp vs Project Function
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
MyCircadianApp
This app tracks sunlight patterns, including sunrise, sunset, and UV index, to help you optimize your exposure. It features a vitamin D timer based on your skin type and environmental factors, and a lux meter to log light exposure. Additional tools include a compass and moon tracker.
- Hourly sunrise, solar noon, sunset tracking
- Live UV index with hourly chart
- Vitamin D timer with personalized recommendations
- Lux meter for light tracking
- Compass for sun directions
- Moon tracker with phases
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MyCircadian shows you what the sun is doing right now, where you are, and what to do with it. SUNLIGHT, HOUR BY HOUR • Sunrise, solar noon, sunset, daybreak and nightfall for your location • UVA and UVB windows, with the current sun angle • Live UV index with an hourly chart and today's peak VITAMIN D TIMER • Recommended time per side based on your skin type, the UV index, cloud cover and how much skin is exposed • Adjust for city, white sand, water or snow • Log every session and see the estimated IUs • See when vitamin D is available today, and how many days are left in the season LIGHT TRACKING • Lux meter that uses your phone's camera • Log light sessions and follow your daily light goal MORE TOOLS • Compass for sunrise and sunset directions • Moon tracker with phase, moonrise and moonset • UV index widget for your Home Screen • Multiple saved locations, imperial or metric units, adjustable text size MyCircadian is a wellness and education tool. It does not diagnose, treat or prevent any condition. Vitamin D figures are estimates. Talk to your doctor about sun exposure and supplements. Terms of Use: https://mycircadianapp.com/terms-of-use Privacy Policy: https://mycircadianapp.com/privacy-policy
Project Function
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With the Project Function App, you can check in to our facility, manage your membership details, and book appointments. - Access digital membership pass - Book appointments and view session balance - Edit personal information and view membership details - Stay up-to-date with announcements from us! Download the app today! Features connectivity to Apple Watch (synced to HealthKit app)
Screenshots
Verdict
The clearest difference is in-app purchases: Project Function at none against MyCircadianApp's 7. On price, update cadence, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. MyCircadianApp sells 7 in-app purchases, starting at $3.99 per month. Project Function asks for nothing beyond the download.
MyCircadianApp ships an update monthly, Project Function every 6 weeks. Both last shipped on November 12, 2026.
| Parameter | MyCircadianApp | Project Function |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (265 ratings) — better | — |
| Positive reviews | 98.6% of reviews | — |
| Number of ratings | 265 — better | — |
| Update frequency | Monthly — better | Every 6 weeks |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Freemium | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Apple Watch — better |
| Requires iOS | 15.1 — better | 15.5 |
| Further details — not scored | ||
| Size | 66 MB | 222 MB |
| Age rating | 12+ | 4+ |
| Developer | Sarah Kleiner Wellness | Project Function LLC |
Bugs and requests
MyCircadianApp
Reported bugs
2 issues- Login screen freezes
- Incompatibility with older devices
Requested features
2 requests- Ability to manually log sun sessions and vitamin D sources
- Option to view upcoming day's sunrise/sunset times
Project Function
Not enough reviews yet to summarise bugs or requests.
In-app purchases
MyCircadianApp
- Monthly7 Days trial$3.991 Month
- Monthly1 Month trial$3.991 Month
- Yearly1 Month trial$36.001 Year
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- Yearly7 Days trial$36.001 Year
- Lifetime$99.00
- Lifetime$179.00
- Lifetime$199.00
Project Function
No in-app purchases
Questions
Is MyCircadianApp free?
Is Project Function free?
Do MyCircadianApp or Project Function have ads?
Which is updated more often, MyCircadianApp or Project Function?
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