To develop an ambulance booking app in 2023, you need to follow a systematic approach. Firstly, conduct market research to understand the current trends and user preferences. Next, define the app's features and functionality, such as real-time location tracking, multiple ambulance options, and an intuitive user interface. Choose a suitable tech stack and decide whether to build a native or cross-platform app. Focus on ensuring data security and compliance with healthcare regulations. Collaborate with ambulance service providers to integrate their services into the app. Implement a robust back-end infrastructure for efficient booking, payment processing, and notifications. Conduct thorough testing to identify and fix any bugs or issues. Finally, launch the app on major app stores and promote it through targeted marketing strategies to attract users and gain traction in the competitive market. Regularly update and improve the app based on user feedback and changing industry requirements.