Independent studios
One coach, an assistant or two, and a steady weekly schedule. C3NTR puts your programming, technique and recovery notes in one place. No second tool, no spreadsheet.
For fitness schools
A knowledge home for your mobility & flexibility studio.
Joint range, tissue health and the work between sessions
→ See a quick tour
Free for up to 30 students
No credit card
UK GDPR · EU (London)
Works offline
Your studio's programming deserves a home
Joint mobility drills get demonstrated but rarely written. Holds and cues vary by coach. The why behind each protocol lives in the coach's head. C3NTR is a quiet place to write it all down once, in your studio's voice.
Who this is for
Studios with multiple coachs
Two or more coachs, several classes a week. C3NTR holds the shared standard so every session draws from the same library.
Studios serving athletes and lifters
You serve strength athletes, lifters and movers. Content locked by level keeps newer members safe while advanced see sport-specific protocols.
Built for teachers, not for IT
Your coach opens the app, taps Edit, and writes the next mobility protocol in plain prose. The next session, members arrive knowing the focus.
Write directly in the app
Like a notepad. New articles are drafts until you publish, so nothing goes live by mistake.
Mobile-first authoring
Edit on the phone between classes or on the way home. The same library, the same edit screen.
A working library in under an hour
Import the starter template in a few taps. Edit anything that doesn't fit. Publish when ready.
Levels, beginner, intermediate, advanced
Content locked by level, in your studio's progression
Tag any article with a minimum level. Beginners see joint basics. Intermediate see longer sequences. Advanced see sport-specific protocols. The same library, the right view per member.
A glossary of mobility and flexibility terminology
Mobility and flexibility has its own movement vocabulary. C3NTR's glossary holds the terms in one place: the exercise names, your studio's preferred cues, and the article each term appears in.
- Mobility
- The ability to move a joint actively through its full range with muscular control.
- Flexibility
- The passive range of motion available at a joint, how far the tissue can be lengthened when relaxed.
- Dynamic stretching
- A form of stretching that uses controlled movement, swinging, circling, or rotating, to take a joint through its range repeatedly rather than holding it still.
- Static stretch
- A held position at the end of a muscle's range, maintained for thirty seconds to several minutes without movement.
- Range of motion
- The arc of movement available at a joint, measured from the starting position to the furthest point the joint can reach.
- CARs
- Controlled Articular Rotations, a systematic method of moving each joint through its largest possible circle under full muscular control.
Workshops, recovery sessions, programming blocks
C3NTR isn't only the library. Schedule the next workshop, post recovery blocks, and let members see what's ahead. Announcements land on their Today tab and events sit on the calendar.
Start from our Mobility & Flexibility template
A working starter with 14 articles, 2 short videos, a 9-terms glossary across 5 tags (Getting Started, Foundations, Practice, Progression, Resources). Import in a few taps, then edit anything that doesn't fit your school. Every article, term and tag is yours from the moment you import.
See the Mobility & Flexibility template Template source:assets/templates/fitness/mobility_flexibility.c3t.md
Inside the app
A look at how the library, articles and grade controls feel in your students' hands.
Plays well with what you already have
Bring your existing programming and exercise notes in with smart Word document import or paste Markdown directly from your coach's archive.
Word documents
Smart import reads headings and turns them into draft articles. You review before anything publishes.
Markdown from any editor
Notion exports, Obsidian notes, Bear, plain .md files. Paste or import.
C3NTR templates
Open .c3t.md format. Schools can share templates with each other without us in the middle.
UK GDPR · DPA 2018
UK GDPR compliant. Hosted in the EU (London).
C3NTR is built around UK data protection law from the ground up. Your school's data sits in the EU on Google Cloud London, the same region we manage from.
UK GDPR + Data Protection Act 2018
Built around UK GDPR Article 6 lawful bases. Subject access requests answered within one calendar month.
Hosted in the EU (London)
Your school's data sits on Google Cloud in the europe-west2 (London) region. No transfer outside the UK or EEA for core operation.
Encrypted in transit
All data is TLS encrypted. Access restricted to personnel with a clear business need.
Account deletion on request
Permanent deletion of personal data and content via in-app or written request.
What C3NTR is, and what it isn't
A library your school owns
Another booking or billing system
Built for how schools actually teach
A generic course builder
Calm, focused reading for students
A feed competing for attention
Start free. Move up when you outgrow it.
Seed
Free forever
Up to 30 students
All core features. No credit card.
Start freeSchool
£39/mo
£32/mo billed annually
Up to 150 students
Push notifications. 1 GB media storage.
Choose SchoolAcademy
£69/mo
£57/mo billed annually
Unlimited students
Multi-instructor publishing. Engagement analytics. 5 GB media storage.
Choose AcademyMember? Show this to your coach.
If you train at a mobility and flexibility studio and you'd love a quiet library you can return to between sessions, share this page with your coach. Most studios start on the free Seed plan in under five minutes.
Common questions
Can members only see their level's material?
Yes. Tag any article with a minimum level. Newer members see only foundations. Coaches see everything, including the deeper programming.
Does it cover FRC, Kinstretch, your method?
Yes. The starter is method neutral. FRC, Kinstretch, your method can adapt the programming without rewriting.
Can my studio customise the mobility and flexibility template?
Yes. Every article, exercise and tag is editable. Add your studio's programming, your favoured progressions and your house cues.
How long does it take to set up?
Most schools have a working library in under an hour. Import the starter template in a few taps, then edit anything that doesn't fit. Starting blank takes a little longer. Allow an hour or two to write your first ten articles. Students can use the app the day you publish.
Do I have to stop using my booking system?
No. C3NTR is a knowledge library for your curriculum, terminology and progressions. Booking, billing and scheduling stay with the tools you already use.
Is there a free plan?
Yes. Seed is free forever for up to 30 students, with no credit card required. Move up to School (£39/mo) or Academy (£69/mo) when you outgrow it.
Other fitness disciplines
Teach a different style? Tell us.
Whether it's a specific mobility & flexibility lineage we don't list, or another discipline entirely, drop us a line and we'll add a starter template. In the meantime, the app already works for any structured curriculum, your library starts blank in a few minutes.
Ready to give your mobility & flexibility students a knowledge home?
Free for the first 30 students. No credit card. A working library in under an hour.
Start free for your school