Film 10 seconds from the side. Get the one change that matters.
What brings you here?
Just looking — open the appSee a real report
Phone clip or one photo10 free analyses / month
Trunk lean: spot on. Next: land under your hips.
What changes for you
Speed · bike
What your position costs in minutes on race day — and what lower wins back.
Estimate at your speedFintelman et al. 2015
Speed · bike
Your aero angles beside 32 pros from Kona 2026. See which gap is worth closing.
Every aero reportFlapp Kona 2026 study
Speed + knees · run
A foot landing in front brakes every step and loads the knee. +5–10% cadence cuts both.
Run videoHeiderscheit et al. 2011
Pain-free · bike
A saddle 5% off changes knee angles by a third. Get the fix in millimetres.
Bike videoBini, Hume & Croft 2011
Clarity
The single fix that matters first. Nothing wrong? We say so.
Every report
Time + money
A pro fit costs hundreds. Re-check every change in 10 seconds, at home.
Free to start
A real report
Not a mockup. A real report: score 70, six flags, every one sourced.
Click to enlarge
Click to enlarge
Score · every joint vs its source · the fix first — see 4 sample reports
Bike fit · before / after · same rider, same road
Hip flagged at 35°. Two fixes later — 99/100. Drag the handle.
◂ Drag to compare ▸
Click to enlarge
Clips too: before and after, locked stroke to stroke.
Our research · Ironman World Championship 2026
Two studies from Kona, every point checked by hand, with the model that measures you.
Study 1 · 32 pros
Hands up, torso low but never flat.
No pro rode flat forearms.
Low — never flat.
Click to enlarge
NewStudy 2 · 31 pros, 68 age-groupers
Same knee, different seat: the pros' hips sit 4–5 cm further forward over the crank.
Pros against age-groupers, men and women alike.
A tie: it isn't saddle height.
Click to enlarge
How it works · no lab, no booking
No lab. No booking. Your phone — and the verdict while you're still warm.
Side-on, hip height, 8–15 s. Or one photo.
Right in the browser. Nothing to install.
33 landmarks. Photo in ~5 s, clip in 30–60 s. Green, amber, red — and one fix first.
Film again. See what moved — and what's just noise.
Side view · captured
Reading 33 landmarks
98 / 100. One amber reading — the knee, a touch past straight. Borderline, not a fault.
Race photo, edited: face, marks and background replaced. Angles measured on the image you see.
Instrument readings
Coaches eyeball form. Flapp measures it.
Your value, the reference band, its source — and a verdict.
Stride-to-stride repeatability, against reference athletes.
Step frame by frame. Every joint as a curve.
Your trunk angle, turned into drag.
Click to enlarge
Fix first
Overall
Your aero position is exceptionally strong, demonstrating excellent balance between aerodynamics and power production.
What's working
Next session
1Focus on maintaining a relaxed, slightly more open elbow angle.
Time-trial rider, after the position change · one real report, unedited
From numbers to orders
Data without direction is noise. Every report ends with orders.
One issue. Why it matters. The drill that fixes it.
The angles to protect — so you don't break a strength.
One cue for your next ride or run.
Want a human too? Coach Notes $12 · Expert Review from a competing triathlete $39 See a full Expert Review (PDF)
Two disciplines, one lens
Running · side view
At full speed you can't see your own stride. Flapp freezes it.
Treadmill or outdoor · any paceRace photo, edited · face & sponsor marks replaced
Cycling · side view
A pro fit is worth it — once. Flapp checks you between fits.
Trainer clip is perfect · 10 seconds is enough
Why now
Don't train through it for months. Check what loads it — today.
Check now 02Fix it in training, not on the start line. Every week counts.
Check now 03Your old setup doesn't carry over. Check before the first long one.
Check now 04Or got advice that contradicts the last? Stop guessing — measure.
Check nowPricing
Every plan covers running and cycling, from a video or a single photo.
| What you get | EnthusiastRecommended forRunnerCyclistUS$5.75US$9 /mobilled yearly as US$69billed monthlyFix my technique | FullRecommended forTriathleteRoad + TT bikeUS$8.25US$13 /mobilled yearly as US$99billed monthlyGet a coach + every bike | |
|---|---|---|---|
| What's off and what to change | |||
| Full reports | 1 free reportwhat's off and why · the drills and angles open only for US$4 | Every clipup to 30 clips a month | Every clipup to 60 clips a month |
| Score and angles | Score on every clip | ✓ | ✓ |
| Overlay video, frame by frame | — | ✓ | ✓ |
| AI coach notes, tips to improve, your angles vs the healthy range1 | AI notes in your free reporttips and angles: US$4 | ✓ | ✓ |
| Adjust landmarks manuallycycling · drag a point and the angles recalculate | Only hip and kneeon a photo | Every jointphoto and video | Every jointphoto and video |
| Your earlier reports open toosubscribe and your history opens in full | — | ✓ | ✓ |
| See that it worked | |||
| Before / after analysis | — | ✓ | ✓ |
| History / trends over time | Score only | Every angle | Every angle |
| Your bikes and setups | |||
| Hip over the crankNewhow far forward you sit over the crank axle | — | — | ✓ |
| Saved setupsthe gear you ride and run with | — | 2 | 10 |
| Compare two bikes or setups | — | — | ✓ |
| Advice from a person | |||
| Expert Reviewa personal plan for the next weeks | US$39 | US$35member price | 1 a year includedevery other one US$29US$29member price · 1 a year included on the yearly plan |
| Keep and share | |||
| Easy-read file for AI | With a US$4 report | ✓ | ✓ |
| Branded PDF report | — | — | ✓ |
Notes: ✓ included; — not included. (1) Healthy ranges come from published research and pro-athlete measures.
Add a pro's review of your first clip · US$35 instead of US$39 · tick it when you choose Enthusiast
Each plan has everything in the one before it · tap one to see it all
Compare plans side by sideEverything in Starter, plus
Add a pro's review of your first clip · US$35 instead of US$39 · tick it when you choose Enthusiast
Fix my techniqueEverything in Enthusiast, plus
Pick any two.
Optional · on top of any plan · a person, not AI
| Coach Notes US$12 | Expert Review US$39 | |
|---|---|---|
| Take it when | You have one report and one question | A race is coming, something hurts, or you got a new bike |
| You get | The first thing to change, and 3 notes pinned on your frames | What he sees, what to fix in what order for 4 weeks, drills, and what to film to check it worked. Written for you, not copied from a list |
| Arrives as | Notes inside your report | A PDF to keep, your numbers at the back · see a sample |
| Ready in | 72 hours | 5 days |
| Get notes on my reportThen: a full review of your next clip, US$27 | Get my plan from a proIncluded once a year with Full, on the yearly plan |
One report, one question. The first thing to change and 3 notes on your frames.
Ready in 72 hours · Then: a full review of your next clip, US$27
Get notes on my reportRace coming, something hurts, new bike? What to fix in what order for 4 weeks, with drills.
Ready in 5 days · a PDF to keep · see a sample
Get my plan from a proIncluded once a year with Full, on the yearly planNotes and reviews are written by Bogdan Kovalenko · Professional triathlete · 2nd at Challenge Gunsan 2026 · Kazakhstan's top-ranked pro (PTO)
Ask before you pay. A real person reads every question and writes back to you.
Prices in USD · cancel anytime · secure checkout by Stripe · billed by Clariva
FAQ
Your next easy session is all the data you need.
Analyze your form — freeFree account · 10 analyses / month · no card required
Your clip never reaches an AI service · clips auto-delete · no ad trackers in the app — privacy policy
