Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).

Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.

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.

Cling Fuzzy Finder - Instant fuzzy find any file, act on it in the same instant.

Listary - Listary is a revolutionary search utility for Windows

Recoll - Recoll is a desktop full-text search tool. Recoll finds keywords inside documents as well as file names.