Desktop app for fitness club membership tracking

Our fitness club is looking for a developer to build a desktop application that keeps track of memberships and visits. Today everything lives in spreadsheets and on paper, so renewals slip through the cracks, plans get confused, and it is impossible to see at a glance who attends regularly and who has frozen their membership. We want a single program that runs on the receptionists' computers, stores its data locally and makes reliable backups. Each client card should hold contact details, a photo, purchase history, the current plan, start and end dates, the number of remaining visits and any freeze periods. We need flexible pricing: unlimited access, packages for a fixed number of sessions, family and corporate memberships, one-off visits, discounts and seasonal promotions. On every visit the receptionist marks the client in by surname or card number, the program deducts the visit automatically and warns when the membership has expired or the sessions are used up. Reminders about memberships that are about to end and one-click renewals are a must. Reporting matters to us: revenue by day and month, client activity, hourly load on the gym, how well each plan performs and churn. We need separate administrator and manager roles with different permissions, printable receipts and export to a spreadsheet. The interface should be simple and clear so a new employee can learn it within an hour. In your reply please suggest a technology stack, a rough timeline and examples of similar projects you have already delivered.