Independent academies
One head coach, an assistant or two, a steady mat. C3NTR puts your positions, submissions and rules notes in one place. No second tool, no spreadsheet.
For martial arts schools
A knowledge home for your Brazilian Jiu-Jitsu academy.
Positions, submissions, the belt system and the language of the mat.
→ See a quick tour
Free for up to 30 students
No credit card
UK GDPR · EU (London)
Works offline
Your academy's craft deserves a home
Sweep variations get taught differently across the four nights of the week. Portuguese terminology lives in head knowledge. The IBJJF rule changes don't reach the white belts. C3NTR is a quiet place to write it all down once.
Who this is for
Academies with multiple coaches
Several professors teaching across the week. C3NTR holds the shared standard so every class draws from the same library.
Competition gyms
You're prepping athletes for IBJJF, ADCC or your local circuit. Content locked by belt keeps newer grapplers safe while purples and browns see deeper game.
Built for teachers, not for IT
Your professor opens the app, taps Edit, and writes the next sweep breakdown in plain prose. The next class, the blue belts arrive knowing the steps.
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.
Belts (white, blue, purple, brown, black) with stripes
Content locked by belt, in your academy's progression
Tag any article with a minimum belt. White belts see fundamentals and survival. Blue belts see escapes and basic submissions. Purple and above see the deeper system. Professors see everything.
A glossary in Portuguese, English and Japanese
BJJ braids Portuguese, English and Japanese. C3NTR's glossary holds the terms in one place: each language, your academy's translation, and the article each term appears in.
- Gi
- The traditional Jiu-Jitsu uniform, a heavy cotton jacket..
- Tap
- The *tap*, the universal signal that a submission is on and your partner should release..
- Guard
- The position where one partner is on their back with the other above, and the bottom partner controls the engagement using their legs. The defining position of Brazilian Jiu-Jitsu.
- Mount
- The position where you sit astride your partner, knees on the mat by their ribs, your weight on their hips. The dominant top position in Jiu-Jitsu.
- Mata Leão
- Portuguese for "kill the lion", the *rear-naked choke*..
- Kimura
- A shoulder lock taking the partner's arm into a figure-four grip and rotating the elbow over the shoulder..
Open mat, comp days, belt promotions
C3NTR isn't only the library. Schedule the next open mat, post comp days, and tell the academy when a promotion is happening. Announcements land on their Today tab and events sit on the calendar.
Start from our Brazilian Jiu-Jitsu template
A working starter with 15 articles, 2 short videos, a 10-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 Brazilian Jiu-Jitsu template Template source:assets/templates/martial_arts/bjj.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 position notes and Portuguese terminology in with smart Word document import or paste Markdown directly from your academy'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 AcademyGrappler? Show this to your professor.
If you roll at a BJJ academy and you'd love a quiet library between training, share this page with your professor. Most academies start on the free Seed plan in under five minutes.
Common questions
Can students only see their belt's material?
Yes. Tag any article with a minimum belt. White belts see only fundamentals. Professors always see everything.
Does it cover both gi and no-gi?
Yes. The starter is written so positions and submissions work in both, with notes on where the gi changes the answer.
Can my academy customise the BJJ template?
Yes. Every article, position and term is editable. Add your professor's lineage, your sweep variations and your competition team's preferred rule sets.
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.
Teach a different style? Tell us.
Whether it's a specific Brazilian Jiu-Jitsu 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 Brazilian Jiu-Jitsu 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