Offline app for field teams: synchronisation, conflicts, photos, signatures and ERP
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Key takeaways
- A gym sells physical access, a coach often sells content: they are not the same product, nor the same economics.
- A membership giving access to in-person classes can be paid outside the stores; a video programme consumed in the app generally goes through in-app purchase.
- The stores' commission on a digital subscription is most often 15%, not 30%, but it must be in your business plan from day one.
- Class booking comes down to three details: waiting list, late cancellation and a reminder the day before.
- A realistic budget: start with an MVP, the most economical option, before a full iOS and Android app — free quote within 24 hours.
A gym that wants "its app" and a coach who wants "their app" are not buying the same product. The gym sells access to a place and to time slots. The coach sells, more and more, a programme, follow-up and content. The first is a booking app with a portfolio of memberships. The second is a content app with a digital subscription.
This distinction is not only a matter of features: it decides whether Apple and Google take a commission on your revenue. It is often the point people discover too late. This guide goes through, in order, the building blocks of a sports and fitness app (in French) — booking, memberships, programmes, wearables, payment — with the budgets and pitfalls of each.
Two models, two economies
Before talking about screens, you need to know what the app sells.
| Gym, studio, club | Coach, coaching brand | |
|---|---|---|
| What the member pays for | Physical access: entry, group classes, sessions | A programme, follow-up, video content |
| Main journey | I see the schedule, I book, I show up | I open today's session, I do it, I log it |
| Critical feature | Schedule, capacity limits, waiting list, access control | Session player, progress, coach messaging |
| Payment | Card, direct debit, often outside the stores | In-app purchase if the content is consumed in the app |
| Retention | The habit of coming, local community | Visible results, relationship with the coach |
Many projects mix the two: a studio that also wants to sell home sessions, a coach who opens a venue. It is possible, but you need to identify the dominant model, because it sets the journey to polish first and the payment scheme.
Class booking: three details make the difference
Showing a schedule and booking a spot, every piece of software does that. What sets a good app apart is the edge cases members run into every week.
The automatic waiting list. The 6.30 pm class is full. The member joins the waiting list; a spot frees up, they are promoted automatically and receive a notification. You have to decide the rules: until when promotion is automatic, what happens if the spot frees up twenty minutes before the class, whether the member has to confirm. It is the most appreciated feature and the one most often botched.
Late cancellation and no-shows. Without a rule, popular slots are booked "just in case" and the class fills up with ghosts. Gyms generally apply a cancellation window (for example 12 or 24 hours), then a penalty: a session deducted from a class pack, a temporary booking block, or a fee. The app must display it clearly at the time of booking, not at the time of sanctioning.
The reminder the day before. A notification the day before and another two hours ahead, with an "I'm not coming" button that frees the spot for the waiting list. It is simple, and it is what keeps the waiting list moving.
On top of that come capacity limits per room and per coach, recurring classes, coach substitutions and access control at the entrance (QR code, badge or integration with the gym's system). On that last point, the estimate depends entirely on the hardware already installed: a QR code displayed in the app and read by a tablet at reception takes a few days, while an integration with an existing turnstile can take several weeks if the supplier has no documented interface.
Memberships, class packs and payment
This is the most underestimated part, because a gym's commercial plans are rarely simple: monthly membership with no commitment, 12-month commitment, 10-session pack, discovery pass, student rate, suspension for injury, referral, multi-site access.
Each plan has to be translated into rules: how many simultaneous bookings, which classes are allowed, at what times, on what date the entitlement expires. We recommend modelling the plans as "entitlements" that can be configured from the back office, rather than hard-coding each offer. The day the sales team invents a summer offer, they create it without a developer.
On the payment side, a gym needs recurring card payments, often SEPA direct debit for long memberships, handling of failed payments (reminders, access suspension) and invoices. The payment providers on the market handle most of it; the work is to connect them cleanly to the access entitlements.
The rule that decides the commission: what is consumed physically (entry to the gym, in-person class, session with a coach on site) can be paid outside the stores, with no Apple or Google commission. What is consumed in the app (video programmes, digital training plans, premium content) generally falls under in-app purchase and its commission. The same app can contain both, with two payment routes.
App store commissions: the real figures
The 30% figure is quoted everywhere. It is rarely the one that applies to a coach or a small business.
| Situation | Apple (App Store) | Google (Play) |
|---|---|---|
| Physical service: gym, in-person class | External payment allowed, no commission | External payment allowed, no commission |
| Digital subscription, small business | 15% through the small developer programme | 15% on subscriptions |
| Digital subscription, standard case | 30% the first year, 15% afterwards for a subscriber who stays | 15% on subscriptions |
| One-off purchase of digital content | 15% or 30% depending on the programme | 15% or 30% depending on the programme |
These rules are shifting. New obligations have been imposed on the stores in the European Union and the United States, with alternative payment options and country-specific rates. They do not make the commission disappear in every case and come with technical conditions. We systematically check the rules in force at the scoping stage, and we advise you to do the same rather than rely on an article, this one included.
Two practical consequences for a coach selling a programme on a monthly subscription:
- With a 15% commission, about 85% of the price remains before VAT and fees. The price has to be built knowing this rate from the start.
- It is tempting to sell the subscription on your website and simply "unlock" it in the app. The stores strictly regulate what the app is allowed to say or show about that external payment. A clumsy button label can get an update rejected — a subject we cover in our article on App Store and Google Play rejections.
Training programmes: an engine, not a video library
For a coach, the temptation is to film fifty sessions and put them in a list. That keeps nobody. What keeps people is the feeling of being followed.
A well-designed programme rests on a simple structure:
- An exercise library: short video, instructions, easier and harder variants, equipment required.
- Sessions made up of those exercises, with sets, reps, rest times, loads.
- Programmes that chain the sessions over several weeks, with progression.
- A log where the member records what they actually did, so the next session adapts.
The coach must be able to build all of this from a back office, without a developer. This is the item that separates an app that lives for three years from one that freezes after three months.
Videos raise a technical question to settle early: adaptive streaming playback so as not to eat the member's whole data plan, and download to train in a basement gym or outdoors with no network. Offline mode has a real cost, which we detail in our article on offline apps.
And AI?
It has its place, provided it stays modest: adjusting the load of the next session from the log, suggesting a replacement exercise when equipment is missing, summarising the week for the coach. An "AI coach" that generates complete programmes without supervision raises physical safety questions that few projects have an interest in taking on. The right use is to augment the human coach, not to replace them.
Wearables: what to connect to what
The question comes up in almost every project: "can we pull the data from the watch?" Yes, but you have to pick the right door.
| Need | Technical solution | Note |
|---|---|---|
| Steps, calories, workouts, sleep | Apple Health (iOS) and Health Connect (Android) | One integration covers most watches and bands |
| Live heart rate during a class | Bluetooth Low Energy, standard heart rate profile | Chest straps and many watches in broadcast mode |
| Detailed activity history | APIs of manufacturers' platforms or sports tracking apps | Access and usage conditions specific to each platform |
| Gym machines (bikes, rowers) | Manufacturer protocol or standard Bluetooth fitness | Very variable, to check machine by machine |
Three points to watch:
- Consent. Heart rate or sleep data are health data within the meaning of the GDPR. They require explicit consent, a clear purpose and appropriate security. If your project moves towards medical monitoring or rehabilitation, read our article on health apps, HDS and the GDPR.
- Store rules. Apple and Google strictly regulate the use of data coming from their health platforms: no targeted advertising, no resale. Your privacy policy must reflect this.
- Real-world testing. A Bluetooth connection is tested with the real sensors, in a real gym, with twenty phones connecting at the same time. The simulator tells you nothing about any of this.
15%Most common commission on a digital subscription
0%Store commission on physical access paid outside the app
4 to 8 wksFor a booking MVP on one platform
How much does a gym or coach app cost?
The table below summarises typical scopes; each one is priced through a free quote within 24 hours, with rates among the lowest on the market. The breakdown of cost items is in our article how much does a mobile app cost in 2026.
| Scope | Typical content | Budget | Timeline |
|---|---|---|---|
| Booking MVP (one platform) | Schedule, booking, waiting list, reminders, simple class pack, minimal back office | On quote | 4 to 8 weeks |
| Full iOS + Android app | + memberships and recurring payment, profiles, programmes, notifications, statistics | On quote | 3 to 4 months |
| Multi-site network or coach platform | + multi-venue, coach marketplace, integrations with access control and existing software, wearables | On quote | 5 to 8 months |
| Maintenance | OS updates, fixes, minor changes, monitoring | Monthly package, on quote | ongoing |
What pushes the bill up, in order: integrations with existing management software or access control, the multiplication of membership plans, video content with offline mode, and real-time wearables. What brings it down: a first scope centred on a single journey, and a deliberately simple back office at the start. Our method for cutting without breaking is described in MVP: cutting the scope without sabotaging the product.
Custom-built or off-the-shelf software?
There is plenty of gym management and booking software, often with a white-label app. It is the right choice when your offer is standard, you have a single site and the member experience is not your selling point.
Custom-built becomes relevant in four situations:
- The experience is your difference: a studio concept, a community, a brand universe that the generic app flattens.
- You sell your own content: programmes, method, follow-up. You want to own the relationship and the data.
- You run several sites with cross-access rules that standard tools handle poorly.
- You want to combine physical and digital in the same membership, with both payment routes.
An intermediate route often works: keep the existing management software for billing and accounting, and build a custom app that connects to it for the member experience. Everything then depends on the quality of the existing software's API — to be checked before signing anything.
On references, we have worked on apps in the sports world such as Decathlon Camp, ARENA 5 or VIKFIT. Each project confirmed the same thing: the member journey is drawn before the technology is chosen.
The mistakes we see most often
- Discovering the stores' commission after development, when the price has already been announced to members.
- Hard-coding the membership plans, and paying a developer for every new commercial offer.
- Neglecting the coach's back office, who ends up managing programmes in a spreadsheet alongside the app.
- Promising the connected watch everywhere without having tested the sensors members actually use.
- Forgetting reception: the person at the desk must see at a glance who has booked, who is late and who is up to date with payment.
Conclusion
A good gym or coach app starts with a business model question, not a list of screens: are you selling access or content? The answer sets the journey to polish first, the payment route and the share of revenue that stays with you. The rest — waiting list, programmes, wearables — is built afterwards, block by block. To see how we approach these projects, see our dedicated page on sports and fitness apps (in French) or our mobile app development offering.
Do you have a gym, studio or coaching project? Let's talk: in a first conversation, we identify your model and the scope of the MVP, then you receive a free quote within 24 hours. You can also call us on +33 1 59 13 25 55.
Sources
- App Review Guidelines — Apple
- App Store Small Business Program — Apple
- Frais de service — Google Play Console
- Santé Connect (in French) — Android Developers
