Comparison

RayDay vs Body Language

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

RayDay

This app helps you understand your daily window for natural Vitamin D production. It calculates optimal sun exposure times based on your location and skin type, providing forecasts and real-time atmospheric data.

Highlights
  • D-Window Calculator
  • Live Solar Path animation
  • 7-Day D-Window Forecast
  • Skin Type Personalization
  • Smart Notifications
  • Real-time Atmospheric Data
  • Home Screen Widget
Features
Read full description

I built RayDay after years of working indoors left me Vitamin D deficient. The fix wasn't another bottle of pills. It was knowing exactly when the sun was high enough so my body could make Vitamin D the way it always has: naturally, on its own. That's all RayDay does: it tells you your daily sun window, personalized to where you live and your skin type, so you can get Vitamin D the way your body was built to. FEATURES: • D-Window Calculator: know exactly when Vitamin D production is possible today and tomorrow • Live Solar Path: a beautiful animated arc showing the sun's position, sunrise, sunset, and the highlighted D-Window • 7-Day Forecast: see your D-Window for the coming week • Skin Type Personalization: your Fitzpatrick type determines how fast you make Vitamin D • Smart Notifications: get alerted before optimal sun days, plus a heads-up when winter's first D-Window returns • Atmospheric Data: real-time UV index, cloud cover, humidity, and altitude • Phase-Aware Design: app colors shift with the time of day. Dawn, daytime, sunset, and night • Home Screen Widget: a quick glance at your D-Window status • Works Worldwide: accurate for any latitude, including polar regions HOW IT WORKS: RayDay uses NOAA solar position algorithms to calculate the sun's altitude throughout the day. When the sun crosses 35° above the horizon, UVB rays penetrate the atmosphere. That's your D-Window for Vitamin D synthesis. The app factors in your Fitzpatrick skin type to recommend exposure durations that hit your daily IU goal without overexposure. Some features require a paid subscription. DISCLAIMER: RayDay is for educational purposes only. Consult a healthcare professional before changing Vitamin D supplementation or sun exposure habits. --- LEGAL: Privacy Policy: http://www.jakubl.com/privacy.html Terms of Use (EULA): http://www.jakubl.com/terms.html SUPPORT: support@jakubl.com X: @jakublaszczyk

About

Body Language

Features
Read full description

Met de Body Language app hebben leden alles op één plek. Schrijf je eenvoudig in voor lessen, bekijk openstaande en betaalde facturen en ontvang belangrijke berichten en updates direct via de app. Zo blijf je altijd op de hoogte en regel je alles snel en gemakkelijk vanaf je telefoon.

Screenshots

RayDay4 screens
Body Language3 screens

Verdict

The call

The clearest difference is in-app purchases: Body Language at none against RayDay's 3. Body Language also leads on iOS requirement (15.0 vs 17.0). 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. RayDay sells 3 in-app purchases, starting at $4.99 per 7 days. Body Language asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 31, 2026 and October 28, 2026 respectively.

Scorecard2 real differences · 7 level
RayDay versus Body Language: the parameters behind the verdict, then further details
ParameterRayDayBody Language
PriceFreeFree
Rating3.0 (2 ratings) — better—
Number of ratings2 — better—
Update frequencyEvery 3 weeksEvery 3 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.015.0 — better
Further details — not scored
Size26 MB41 MB
Age rating4+4+
DeveloperJakub LaszczykLogiFit

In-app purchases

3 purchases

RayDay

Subscriptions3
  • RayDay Weekly3 Days trial$4.997 Days
  • RayDay Yearly$24.991 Year
  • Early Supporter Yearly1 Year trial$24.991 Year
None

Body Language

No in-app purchases

Questions

Is RayDay free?
RayDay is free to download, with in-app purchases available.
Is Body Language free?
Body Language is free to download, with no in-app purchases.
Do RayDay or Body Language have ads?
Neither RayDay nor Body Language shows ads.
Which is updated more often, RayDay or Body Language?
RayDay ships an update every 3 weeks, and Body Language every 3 weeks. Most recently, RayDay was updated on October 31, 2026 and Body Language on October 28, 2026.

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