BuyHub is a shopping application designed for collectors that aggregates product listings from over 100 online marketplaces into a single search interface. The app allows users to search across platforms such as Vinted, Wallapop, eBay, Facebook Marketplace, Depop, Mercari, and others simultaneously. It is available in 129 countries and supports both web and mobile use, with real-time alerts on the mobile version. Key features include Radar, a price tracking tool that notifies users when a new listing matching their criteria appears. The app supports multi-term search, which merges results from several search queries and removes duplicates. Users can build advanced searches with filters and save them for quick access. The app also enables direct purchasing by allowing users to sign in to their accounts on supported stores within the interface. Paid plans (Pro and Max) offer the ability to save multiple accounts per store and switch between them. Additional functionality includes automatic currency conversion and translation of listing titles into the user’s language. Typical use cases involve collectors searching for specific items such as vintage cameras, die-cast cars, handheld consoles, or trading cards. The workflow begins with entering search terms or setting a Radar for a desired item. The app displays results from all connected marketplaces, with details like seller country, time since listing, price range, and condition. Users can then apply filters, save searches, and proceed to purchase directly on the original marketplace page without leaving the app. The application requires an internet connection and is available as a mobile app for real-time Radar alerts. It supports linking accounts for multiple stores, and the interface provides advanced filtering options not commonly found on individual marketplace platforms. The app is intended for users who regularly buy from multiple secondhand or collector-focused marketplaces and want a unified search and monitoring tool.