Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.
Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).
DocFetcher - DocFetcher is a portable German/English open source desktop search application.
Listary - Listary is a revolutionary search utility for Windows
Agent Ransack - Agent Ransack is a tool for finding files and information on your hard drive fast and efficiently.
Alfred - Alfred is an award-winning app for macOS which boosts your efficiency with hotkeys, keywords, text expansion and more. Search your Mac and the web, and be more productive with custom actions to control your Mac.