The best Martial Arts on Rails alternative is Exercise.com.

Exercise.com vs Martial Arts on Rails: with adequate scheduling software, Martial Arts on Rails works well for certain gyms, but top tier gyms who want to succeed online and in-person, and deliver all varieties of workouts at scale, send fitness assessments, and use powerful gym booking and billing automations are all things that you can get with Exercise.com, so you can run your entire business in one place.