BASELINE01
Start with a comparable baseline
Guided capture helps repeat framing, pose, and distance. Photo Match shows when a comparison deserves more caution.
Your physique, documented
Turn progress photos intoa body of evidence.
Corpus connects guided check-ins with estimated body-composition trends, recovery context, and your training history—so you can see what changed and decide what deserves attention next.
14-day trial with the yearly plan. Or choose $7.99/mo. Cancel anytime.
Estimated, not clinicalNo ads or ad trackingApple Health is optionaliPhone, iOS 26+
Documented progress
The scale showed ten pounds. Corpus showed the whole change.
Jordan's product journey moved from a 78 to 91 score while estimated body fat trended from 17.0% to 11.8%. One story, presented as evidence—not a promise of typical results.
Documented product journey · Individual results vary
StartLatest
Corpus score7891
Estimated body fat17.0%11.8%
Logged weight187.8 lb177.6 lb
Corpus score
78 → 91
+13
The Corpus record
Every check-in makes the story clearer.
A photo on its own is just a moment. Corpus connects each record to what came before—and what deserves your attention next.
TREND02
Give the change context
Score, estimated composition, FFMI, and eight muscle regions live in the same history—without turning a photo into a clinical scan.
8 regions · one trend
DECISION03
Take the record into the next session
Use what you have accumulated to see trend, focus, and optional recovery context without starting from zero.
Corpus score78 → 91
From evidence to a decision
What deserves attention now?
Corpus does not try to prescribe your training. It brings together what you have recorded so the next decision has more context than a guess.
Optional recovery context from Apple Health
Sleep, HRV, resting heart rate, wrist temperature, and respiratory rate are optional. Photo-based tracking still works without Apple Health.
Coach grounded in your history
“Your record shows where attention may be worth more right now.”
Next milestone
See the distance to the goal you set.
Plan
Keep macro targets connected to your history.
Weekly streak
Protect your rhythm without turning one missed day into guilt.
Progress beyond weight
When the scale misses the story, your history keeps it.
Matched photos, logged weight, and the same estimated signals give you more context than any one number alone.
Jordan · documented product journey
A visible change, measured across the same journey
Score 78 → 91 · Estimated body fat 17.0% → 11.8% · Logged weight 187.8 → 177.6 lb
Score
+13
Body fat
−5.2%
Weight
−10.2 lb
Anonymized · permissioned journey
The scale barely moved. The trend still did.
An anonymized six-month product journey: score 77 → 80, estimated body fat 24.5% → 22.5%, and 26 check-ins.
Permissioned product journeys. Estimates are not medical measurements. Individual results vary.
Why the scale can hide body recomposition →Method before certainty
Useful estimates, with the limitations left in.
Corpus is a progress tool—not a medical device, DEXA replacement, or promise that every photo is perfectly comparable.
Capture quality is checked
Photo Match evaluates factors such as framing, pose, distance, and lighting so you can judge comparison quality.
Trends matter more than decimals
Photo-based body-composition values are estimates. Repeating the method is more useful than treating one result as clinical truth.
No advertising business model
Corpus is supported by subscriptions. Check-in data is not sold or used to target ads.
You control optional health access
Apple Health data is used only when you choose to connect it for recovery context.
Corpus Notes
Better check-ins start with better questions.
body composition
The Navy Body Fat Formula: How It Works and How Accurate It Is
The Navy formula estimates body fat from height, neck, waist and hips. Studies against DEXA found it reads about 4 to 6 points low and can miss weeks of fat loss.
Oct 2026Read the guide →
training recovery
Resting Heart Rate by Age: A Chart Built From Real Data
A resting heart rate by age chart from US survey and wearable data: kids fall from 129 to 78 bpm, adults average 65–72 bpm, and women run a few beats higher.
Oct 2026Read the guide →
progress tracking
Spren App vs. Corpus (2026): Cost, Accuracy Claims and What You Get
What the Spren app costs on the US App Store, what its accuracy claims rest on, and how it compares with Corpus for weekly body-fat tracking. Disclosed comparison.
Oct 2026Read the guide →
Simple pricing
Try the full product. Keep it if it earns the habit.
Every plan includes the complete Corpus experience. Choose the billing rhythm that fits you.
Monthly
$7.99/mo
Billed monthly
Yearly
$49.99/yr
Billed yearly · $4.17/moSave 47%
14-day free trial with yearly
Included with Corpus
- Guided photo check-ins
- Score and estimated composition trends
- Eight muscle-group views
- Coach and next-step guidance
- Optional Apple Health recovery context
Cancel anytime in App Store settings.
Final price and trial eligibility are shown before purchase in the App Store.
Questions
Before you ask
How accurate is a photo-based body fat estimate?
Photo-based estimates will not match a DEXA scan to the decimal, and Corpus does not claim they will. Consistent capture conditions can make the trend more useful over time, but every result remains an estimate rather than a clinical measurement.
Is this a replacement for a DEXA scan?
No, and it isn't trying to be. A DEXA scan is a clinical-grade snapshot you take once or twice a year. Corpus is built for the other 363 days, when a lab visit isn't realistic but you still want a real signal.
Why is Corpus iPhone-only?
Corpus is built specifically for iOS 26 and Liquid Glass, and it reads recovery signals from Apple Health. Building it properly for one platform came before building it broadly for several.
What happens to my photos?
A check-in photo is sent for analysis and handled as described in the Corpus Privacy Policy. It is not sold, used for advertising, or placed in a public photo library. Review the policy for current processing, storage, and deletion details.
Do I need to connect Apple Health?
It's optional, but it's what powers your Recovery score. Without it, everything based on your photo, check-ins, score, body fat, FFMI, muscle groups, still works exactly the same.
How often should I check in?
Once a week is enough for the score and photo comparisons to mean something. Recovery, Quick Log, and the Coach are built for daily use in between, so the app has a reason to open every day, not just check-in day.
Can I cancel anytime?
Yes. You can manage or cancel the subscription in your App Store settings. The App Store shows the applicable trial and renewal terms before purchase.
Corpus for iPhone
See your work as a trend—not a guess.
Build a baseline, check in consistently, and know what deserves your attention next.
14-day trial with yearly. Monthly and yearly plans available.