Trialist — Health Experiments
Find out what actually works
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Run simple experiments on yourself, watch your Apple Health data, and find what actually moves your sleep, recovery and energy — all private, all on your iPhone.
Stop guessing whether that supplement, bedtime, or new habit is doing anything. Trialist turns
your iPhone into a personal lab: change one thing, and watch what actually happens in your own
health data.
HOW IT WORKS
1. Pick something to test — magnesium before bed, an earlier last meal, cold plunges, no late
caffeine, a new routine. Anything you can do (or skip) on a given day.
2. Log it in a tap. Trialist reads your Apple Health data in the background.
3. See the difference. Trialist compares your "did it" days against your personal baseline and
shows you the change — with the sample size and strength behind every number.
WHAT MOVES YOUR DATA
The heart of Trialist is one honest question: what actually moves your sleep, HRV, resting heart
rate, steps, or energy? Trialist ranks your habits, doses, and journal tags by their real
day-to-day effect — not by hype. Dig into dose-response ("how much is enough?"), timing effects
("does it matter when?"), and change-points ("when did things shift?").
RATE YOUR DAY
Give the day a quick 1–10. Over time Trialist learns what separates your great days from your
rough ones — and even which way the arrow points (does better sleep make a better day, or the
other way around?).
A JOURNAL THAT EXPLAINS THE OUTLIERS
Capture what you ate, how you felt, or a gut symptom in a tap, and tag the day (sick, traveling,
big meal, hard workout). Trialist lines those entries up against your metrics — so you can catch
the food behind a rough night, or the symptom that shows up a day after a trigger.
BUILT ON HONESTY
Most health apps overclaim. Trialist does the opposite. Every result shows how much data is
behind it (Limited / Good / Strong), calls associations what they are — associations, not proof —
and lets you exclude sick or travel days so they don't skew your results.
PRIVATE BY DESIGN
- No account. No sign-up.
- No cloud. Everything stays on your device.
- No third-party tracking or ads.
- Export your full data anytime as JSON, or a clean PDF to share with whoever you choose.
TRACK EVERYTHING IN ONE PLACE
- Binary habits, A/B comparisons (Running vs Cycling), dosed supplements, and timed routines.
- A visual calendar of every trial, streaks, and adherence.
- A day journal with tags to capture context (sick, traveling, big meal, hard workout…).
TRIALIST PRO
Trialist is free to start — create experiments, log every day, and see how your "did it" days
compare to your baseline. Trialist Pro unlocks the full insight engine: "what moves your data",
dose-response ("how much is enough?"), timing effects ("does it matter when?"), change-point
detection, head-to-head experiment comparison, food-to-symptom lag, and the good-days analysis.
A few free insights each day, so you can try before you commit.
—
Trialist is for personal, informational, and educational use only. It is not a medical device and
does not diagnose, treat, cure, or prevent any disease or condition. Always consult a qualified
health professional before changing your health routine.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
A big update focused on understanding what actually works for you:
• What moves your data — a new ranked view of the habits, doses, and days that shift your sleep,
HRV, energy and more, by real effect size.
• Rate your day — a one-tap daily score, plus an analysis of what separates your good days from
your rough ones (and which comes first).
• Journal — capture meals, symptoms and context in a tap, then see how they line up with your
metrics (like a food that shows up in your gut a day later).
• A smoother start — pick a goal and Trialist sets up your first experiment for you.
• Sharper, more honest stats — clearer confidence levels, change-point detection, and the option
to exclude sick or travel days.
Thanks for experimenting with us. Questions or ideas? We read every message.
The developer, RIKU ROBERT BRANDT, 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 Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- RIKU ROBERT BRANDT
- Size
- 19.4 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
13+
- 13+
- Infrequent
Medical Treatment information
Contains
User-Generated Content
Health or Wellness Topics
- In-App Purchases
Yes
- Trialist Pro — Lifetime $49.99
- Trialist Pro — Annual $19.99
- Copyright
- © 2025 Riku Brandt