There are several options available for creating a fashion brand’s website, app, and catalog (lookbook). Here are some popular choices:

1. Shopify: Shopify is a popular e-commerce platform that allows you to create an online store with customizable themes, a user-friendly interface, and the ability to integrate third-party apps.
2. WooCommerce: WooCommerce is another e-commerce platform that works as a plugin for WordPress websites, allowing you to create an online store with a wide range of customizable themes and plugins.
3. Squarespace: Squarespace is a website builder that offers modern and professional templates with a drag-and-drop interface, making it easy to create a website and online store.
4. Wix: Wix is another website builder that offers customizable templates, a drag-and-drop interface, and the ability to add e-commerce functionality to your site.
5. Magento: Magento is a powerful e-commerce platform that allows for advanced customization and flexibility, making it a good choice for larger businesses with more complex needs.
6. Adobe Creative Suite: Adobe Creative Suite offers a range of tools for creating catalogs and lookbooks, including InDesign for layout design, Photoshop for image editing, and Illustrator for creating vector graphics.
7. Canva: Canva is an online design tool that offers templates and customizable graphics for creating lookbooks and catalogs.
8. FlipHTML5: FlipHTML5 is a digital publishing platform that allows you to create interactive catalogs and lookbooks with page-turning effects, multimedia content, and more.

Ultimately, the best option for your fashion brand will depend on your specific needs and budget. It’s important to choose a platform or tool that is user-friendly, customizable, and scalable, allowing you to grow your business as needed.