See it in action
Your personalised technique report.
Film your freestyle, upload it, and get a detailed breakdown of your technique reviewed by a real coach.
Tumbl watches your freestyle and tells you what matters most.
Film it. Upload it. Get better.
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See it in action
Film your freestyle, upload it, and get a detailed breakdown of your technique reviewed by a real coach.
What swimmers say
“The analysis itself was excellent. I liked that it focused on one key improvement area.”
F.W. — March 2026
“Genuinely thrilled with how clear and specific the feedback was. I feel like I know exactly what to work on.”
J.G. — March 2026
“Having the 'think this while you swim' cue was really useful, and defo had a positive impact on my swimming.”
A.L. — March 2026
“The app is fantastic — easy upload, really informative and intuitive.”
L.J. — April 2026
How it works
No complicated setup, just your phone and a pool.
Get someone to film your freestyle from the side of the pool.
Upload the video to Tumbl. We start analysing straight away.
Personalised technique feedback reviewed by a real coach.
What happens behind the scenes
Every video goes through two stages. Technical analysis using neuro-symbolic architecture, then a real coach review. So you understand what's happening in your swimming and why it matters.
Layer one
Tumbl checks over 40 areas of your freestyle. Catch, pull, kick, breathing, rotation, timing, and more.
Layer two
A real coach reviews your results, adds their expertise, and helps you prioritise what matters most.
Who it's for
You don't need to be fast. You just need to want to get better.
Swimmers who want to improve but don't have access to a private coach.
Coaches who want a tool to give more detailed feedback to their swimmers.
Triathletes, masters swimmers, club swimmers, keen improvers.
Anyone who's ever finished a swim and thought “am I even doing this right?”
About
Hi, I'm Char. I love swimming. I've spent most of my life in the pool, first as a junior elite swimmer and then as a coach.
The thing I notice most, coaching adults every week, is how many swimmers are stuck. They work hard, but they can't see what they're doing in the water and they've got no way of knowing what to focus on.
Getting someone qualified to watch your stroke can often cost £100-200 per analysis. That prices out most people, and even if you can afford it, you get feedback once and then you're on your own again.
I work in tech, and I kept coming back to this idea that there had to be a way to get good feedback to more swimmers, more often. That's what I'm building with Tumbl.
Find out more about the philosophy behind Tumbl →Swimmers, coaches, and curious beginners figuring it out together. Stroke tips, drill ideas, and what we're working on next.
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