Mobile App for Equipment Service Business

I'm looking to have a mobile app developed to manage my equipment service business. The app should be developed for both the iOS and Android platforms. The key feature of the app should be scheduling and booking - customers should be able to view available services and book appointments directly. Other features should include user registration and equipment tracking, so customers can view their service history. I do not need to integrate the app with any other software or systems, and it should be a standalone application.