The tutorial on the RapidAPI blog discusses how to integrate Skyscanner Flight Search API with Dark Sky API and City Geo-Location Lookup API to create a practical application. APIs, described as building blocks for software development, facilitate faster development cycles and simplified debugging, though challenges arise due to the multitude of available APIs with varying interfaces. RapidAPI offers a marketplace to streamline API selection, testing, and billing. The tutorial demonstrates how to combine the three APIs to develop an application that allows users to search for flights, obtain geographical coordinates for specified locations, and access weather data for these locations on specified past dates. The application aims to enhance trip planning by providing flight options alongside weather conditions from previous years. The tutorial provides insights into API functionalities, endpoints, and integration techniques, underscoring the potential of APIs to create real-world applications.