Gym OS
Speculative membership + attendance + trainer-scheduling system for the small independent gyms that run on a paper register, a WhatsApp group, and the owner's memory. Android-first, QR check-in, no kiosk hardware required.
Overview
Gym OS is a speculative product we designed for the thousands of single-location gyms that run on spreadsheets, paper registers, and the owner's memory. It's not a shipped product; it's a design and architecture we'd execute on if the right gym owner partnered with us. The brief we set ourselves: what would gym software look like if you designed it for the actual business, not the business model the SaaS industry wants it to be?
The problem
A typical 100-member neighbourhood gym operates with three persistent frictions. First: tracking who paid and when — most memberships are cash, monthly, expire on different days, and live in a ruled notebook the owner flips through before deciding whether to say 'pay karna hai'. Second: attendance — the owner wants to know who actually shows up vs who pays and never comes (useful for renewal conversations, retention, class scheduling) but has no way to record it that doesn't annoy members. Third: trainer scheduling — when there's one trainer doing personal-training slots, the booking happens over WhatsApp and collisions happen weekly. Existing gym management software (GymMaster, Wodify, SmartReceipt) is priced and configured for 300-member fitness clubs. Nothing we found fits a 100-member owner-operated gym with one trainer.
What we built
- Designed the app around one home screen: today's expiring members (top of screen), today's attendance count, today's trainer slots. The three things the owner needs to see in 10 seconds.
- QR check-in as the member interaction: a printed QR code sits on the wall, members scan it on the way in, their name pops on the owner's live attendance board. No card, no kiosk, no app install for members.
- Built an expiry reminder flow: Firebase Cloud Function runs daily, finds members whose membership expires in 3 days, fires a WhatsApp reminder using the Business API. Owner gets notified when someone's 7 days overdue so they can have the conversation in person.
- Trainer slot booking as a shared calendar the owner owns — members don't book themselves, they WhatsApp the owner who has a single 'Trainer' tab showing the trainer's week. Prevents the collision problem without forcing members onto an app.
- Used Jetpack Compose with Material 3 dynamic colour, designed for the specific reality of a gym: the owner's phone is sweaty, sometimes used with one hand while holding a towel, in patchy WiFi. High-contrast UI, big touch targets, offline-first with Room caching.
Key features
- QR code check-in — member scans, owner sees live attendance board
- Expiring-memberships home screen — see today's expiry risks in 10 seconds
- Automatic WhatsApp renewal reminders 3 days before expiry
- Trainer slot calendar (single surface, owner-managed, no member booking)
- Offline-first — Room + Firestore sync, owner's phone works during WiFi drops
- Cash payment logging — we track when, you still hold the cash
- Member photo on QR scan so the owner recognises who just walked in
- CSV export for accounting at month-end
Results
Concept, not shipped. What exists: a Figma file with the three primary flows, a Kotlin prototype that demonstrates QR check-in + Firestore sync, a documented WhatsApp Business API integration plan, and this case study. If you run a gym in India or you're building for the SMB fitness segment, tell us — we'd rather ship yours than wait to build ours.
A concept design + Kotlin prototype centred on the one thing that actually breaks these gyms: the owner forgetting whose membership expired this week and letting them keep training without paying. Members check in by scanning a QR code on the wall; the owner sees a live attendance board and automatic WhatsApp renewal reminders 3 days before each expiry.
I know every member. The problem is I know them too well — I don't remind them to pay and then two months go by.
What we learned
- Designing for a 100-member gym isn't 'scaled down' 300-member gym software — it's a different product. The real owner-operator doesn't need most of what enterprise fitness SaaS ships.
- QR check-in beats membership cards for this segment because cards require hardware ($$) and get lost. A laminated QR on the wall costs ₹20 and lasts a year.
- Scope discipline is the feature. Saying no to class booking and lead tracking made the home screen usable.
Stack
Have a similar project?
Tell us what you're building and the deadline. We'll reply in 24 hours — with either a scoped proposal or an honest "not our fit".