Keld Wellspring

Your body's sunstone

Only for iPhone

Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.

iPhone

Keld finds the patterns between your body and the world around you — patterns that are yours, not an average in some faceless study. Keld is a personal weather service for your body. It quietly correlates the signals from your Apple Watch and iPhone — heart rate variability, sleep, breathing, steps, blood oxygen, and dozens more — with the world you actually live in: the weather above you, the air you breathe, the pollen drifting through, the sound around you, and the places you spend time. When a real pattern emerges, Keld names it. Not a number. Not a chart. A two-word name, a unique sigil, and a quiet evidence card explaining what makes it yours. FOUR KINDS OF PATTERNS • Body — patterns inside your biology • Weather — patterns in the air, light, and sky • Geometric — patterns at YOUR specific places • Hybrid — patterns that weave biology, weather, and place together A LIVING LIBRARY Every Element gets a unique sigil, a haiku-style name, and a mathematically honest confidence tier — Proven, Forming, or earlier. Tap any Element to see exactly what supports it. WHAT'S COMING NEXT A dedicated Forecasts tab shows your next 24 hours of biometric modes, the 10-day weather, and the planets above your head right now. ATMOSPHERE PANELS Smooth, real-time charts for temperature, pressure, humidity, wind, air quality, pollen, audio exposure, and place density. PRIVACY BY ARCHITECTURE Your raw Apple Health data never leaves your device. Your precise location is snapped to a 500-meter grid on-device before any analysis. No account. No email. No password. Anonymous device identifier only. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

  • 5.0
    out of 5
    1 Ratings

Your biggest Keld update yet — your patterns are now a living Field Guide of animals, with honest science behind every one. THE FIELD GUIDE • Your Library now opens on the Field Guide — a complete visual rebuild of your discovered patterns ("Elements"). • Patterns are sorted into five strength bands at a glance: Beacon, Signal, Pattern, Whisper, and Noise. • Each pattern is a card showing its artwork, its name (color-coded by what it connects: your body, the weather, a place), how strongly the two signals track together, and its strength. • A tap on the ⓘ gives plain-English definitions of every band. YOUR ELEMENTS ARE NOW ANIMALS • Every body pattern now has an emblem creature — your heart is a Horse, movement a Wolf, sleep a Sloth, and more. • Strong, confirmed patterns earn their own distinct species, and curated scientific names appear right under the common name. • Names read naturally — a plain animal name for a pure-body pattern, or something like "Windy Wolf of Overland Park" when weather and a place are involved. • Place-based patterns now show a small place icon (Home / Work / Outdoor) in the corner of the card. • Pure weather and pure place patterns keep their own dedicated artwork. HONEST SCIENCE, IN PLAIN LANGUAGE • The small technical stats on each Element are replaced by a sentence you can actually read — e.g. "the two signals track 48% of each other's movement, statistically confirmed across N paired readings." • Each pattern is marked Confirmed or Provisional so you always know how much to trust it, with the statistical methods cited at the bottom of the Field Guide. • Keld keeps the patterns it can honestly stand behind and lets go of the ones it can't — so some older, weaker patterns may quietly retire. • Patterns now carry a Growing / Steady / Decaying trend pill as they strengthen or fade over time. • Keld describes only what was observed in your own data — never "X caused Y." NEW KINDS OF PATTERNS • Sleep and other once-a-day signals (sleep, weight, VO₂max) can now form Elements — including how a short night can follow you for a day or two. • Ambient sound and air quality are now correctly treated as part of your environment. • Smarter, more descriptive pattern names that match how the signals actually move. • "FIELD NOTES" panels surface the day-by-day aftermath of an event in plain, observational language. PULSE & PATTERN OF THE DAY • Pull Pulse to grab your latest readings and re-check every pattern (Keld also updates on its own). • Pattern of the Day has a colored strength ring and an always-visible pointer, so the dial reads clearly even at zero lag. • Negative correlations now show their two metrics moving oppositely everywhere — cards, detail, share, and video. SHARE VIDEOS & IMAGES • Sharing an Element or your Saga as a video now leads with its real artwork and a faithful capture of its detail card. • Cleaner opening cards, connection counts that agree across the video, and faster generation. APPLE HEALTH RELIABILITY • The Apple Health permission sheet now opens cleanly every time during setup. • A "Pull my heart data" banner appears if your Apple Watch is logging activity but heart data isn't coming through — and honestly tells you when a permission needs to be re-enabled in the Health app. • Settings can flag a vital that looks turned off and points you to the exact place to fix it. PERFORMANCE & POLISH • Reopening the app returns you straight to where you left off — no splash screen on resume. • Search is back across your Library pages, place labels fit on one line, and a long list of stability and reliability fixes throughout.

The developer, Brian Gansereit, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Linked to You

    The following data may be collected but it is not linked to your identity:

    • Health & Fitness
    • Location
    • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

The developer has not yet indicated which accessibility features this app supports. Learn More

Seller
  • Brian Gansereit
Size
  • 118.7 MB
Category
  • Health & Fitness
Compatibility
Requires iOS 15.1 or later.
  • iPhone
    Requires iOS 15.1 or later.
  • iPod touch
    Requires iOS 15.1 or later.
  • Mac
    Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
  • Apple Vision
    Requires visionOS 1.0 or later.
Location
  • This app may use your location even when it isn’t open, which can decrease device battery life.
Languages
  • English
Age Rating
16+
  • 16+
  • Contains
    Unrestricted Web Access
    User-Generated Content
    Health or Wellness Topics
In-App Purchases
Yes
Copyright
  • © 2026 BioSignal AI