dnGREP - dnGrep allows you to search across files with easy-to-read results.
Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).
AstroGrep - AstroGrep is A Microsoft Windows GUI File Searching (grep) utility.
Listary - Listary is a revolutionary search utility for Windows
PowerGREP - Quickly search through large numbers of files on your PC or network using powerful text patterns to find exactly the information you want. Search and replace with plain text or regular expressions to maintain web sites, source code, reports, ...
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.