Personal trainer app development
Clients, plans, sessions, and invoices, in the coach's pocket.
A personal trainer app gives a coach one place for clients, workout and diet plans, session scheduling, workout logging, and invoices, and gives each client their plan on their phone. Acasa Labs builds them. GymFast Pro, part of our gym platform GymFast, does this today for independent trainers who work without a gym behind them.
The problem
A coach's business runs on WhatsApp and a notes app.
Independent trainers send plans as PDFs or photos, keep sessions in a phone calendar, log a client's lifts on paper, and chase payments by message. It works for ten clients and falls apart at thirty. Clients lose the plan, sessions get double-booked, and invoices go out late or not at all. The coach ends up doing admin in the evenings instead of coaching. A trainer app replaces the pile with one system that the coach and every client use.
What we build
- 01
Clients and their history
Every client's details, plans, sessions, and progress in one record the coach can pull up between sessions.
- 02
Workout and diet plans
Plans built once and assigned to clients, who follow them on their phone and log what they actually did.
- 03
Session scheduling
Sessions booked, moved, and reminded automatically, so the coach stops being the calendar.
- 04
Invoices and payments
Client invoices raised from the app, with what is paid and what is due in one place.
From production
How GymFast Pro does it.
Built for coaches without a gym
GymFastGymFast Pro gives independent trainers clients, workout and diet plans, session scheduling, workout logging, and client invoices, with no gym account behind them.
Session reminders on a schedule
GymFastSession reminders, like every GymFast reminder, run as scheduled edge functions, so they go out whether or not the coach remembers to send them.
A logged session survives bad signal
GymFastA workout in progress is saved on the device, so a dropped connection mid-session does not lose what the client logged.
One API under every app
GymFastThe trainer app shares one token-authenticated mobile API with GymFast's staff and member apps, so it is part of one platform, not a separate product to maintain.
Honest trade-offs
Use GymFast Pro, or build your own app?
If you coach clients and want an app for them this week, use GymFast Pro. Build your own when the app is the product you sell: a coaching brand with its own programs, an online coaching business with hundreds of clients, or a fitness creator who wants their own name on the app store listing. We can build it on GymFast's foundations, so you start from a working base instead of a blank page.
What we reach for
- Expo, React Native
- Supabase Postgres with row-level security
- Supabase Edge Functions
- RevenueCat
- Next.js
Proof
Shipped, not pitched.
01Our product
GymFast
Members, billing, classes, and workout plans for a gym, in one platform and three apps.
Gym management software for gym owners and personal trainers. A web dashboard and a staff app run members, plans, invoices, enquiries, and classes; members get their own branded app; GymFast Pro gives independent trainers the same tools for their clients.
Web dashboard · iOS · Android · Staff, member, and trainer apps
Questions
Personal trainer apps questions we get asked.
What should a personal trainer app include?
Clients, workout and diet plans, session scheduling and reminders, workout logging, and invoices. Progress photos and weekly check-ins are common additions.
Can clients log workouts with bad signal?
Yes. GymFast saves a workout in progress on the device, so a dropped connection does not lose it. We design custom builds the same way.
Can I sell coaching subscriptions in the app?
Yes. Digital subscriptions sold in the app go through Apple and Google in-app purchase, which we handle with RevenueCat. In-person sessions can be invoiced directly.
Can the app carry my own brand?
GymFast already themes its apps in each gym's colors. A custom build can go further, with your own name and icon on the store listing.
Can it work for a team of trainers?
Yes. GymFast's six-level role hierarchy, from owner to member, is enforced in the database, so a coaching business with several trainers can give each one the right access.
Can clients see what they owe?
GymFast Pro lets trainers raise client invoices, and GymFast's member app already shows members their invoices. A custom trainer app can show each client what is paid and what is due.
Personal trainer app development
Coaching clients, or building a coaching app?
Tell us which. We will show you GymFast Pro, or scope the app with your name on it.