If you’re searching for open-source software to create directory websites specifically for apps, here are some options for free software:

• Eventmie-pro: Eventmie is an Event planning and management Laravel package. With Eventmie, launch a dedicated platform for Event planning on your domain. Streamline the event planning process through automation. Eventmie is secure, scalable, production-ready.
  Just install it into a brand new Laravel application or an existing one and start selling events for free.
• DirectoryHub: DirectoryHub is an open-source directory software built with Laravel PHP framework. It provides features for creating and managing directory websites, including categories, listings, search, and user reviews. You can customize it to focus on app listings.
• PyroCMS: PyroCMS is an open-source CMS built with PHP Laravel framework. It provides a flexible platform to create directory websites, including app listings. You can customize it to suit your specific requirements.
• Laravel Business Listings: Laravel Business Listings is an open-source Laravel package that allows you to create business and directory websites. It can be customized to focus on app listings and offers features like categories, search, user reviews, and ratings.
• phpListings: phpListings.com is an all-in-one business listings directory website solution with an intuitive and user-friendly search facility, administrator and member panels, automated invoicing and everything you need to start and maintain a profitable directory website.
  
  These options provide you with Laravel-based solutions for building directory websites, allowing you to leverage the power and flexibility of the Laravel framework.