Aplikasi Mobile Sistem Booking Jadwal Kelas Fitness dengan Integrasi Pembayaran Qris Berbasis Flutter

As public interest in a healthy lifestyle increases, the need for an efficient and integrated fitness center management system is increasing. At Salma Fitness Wonogiri, the process of setting schedules and booking classes is still carried out manually through short messages or direct confirmation, so it often causes various problems, such as inaccurate attendance data, the number of participants that exceed class capacity, delays in submitting schedule information, and recording cash payments that are less efficient and prone to errors. This research aims to design and develop a mobile application for a fitness class schedule booking system that is integrated with Flutter-based QRIS digital payments. This application provides user authentication features, real-time class schedule information, class bookings, and non-cash payments through QRIS. Firebase is used as a backend for user authentication and storage of schedule, transaction, and booking history data. The development method applied is Agile Development, so it allows the development of features gradually according to user needs. Initial test results show that the app is able to speed up the booking process, minimize data entry errors, improve the accuracy of the number of class participants, and make it easier to manage payments and transaction reports. Thus, this application is expected to increase operational effectiveness and service quality at Salma Fitness Wonogiri.