Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).
TagSpaces - TagSpaces is an open source platform for personal data management. With TagSpaces you can manage and organize the files on your laptop, tablet or smart phone.
Listary - Listary is a revolutionary search utility for Windows
TagFlow - TagFlow is an intelligent files manager that use tags for organize your documents.
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.
Tabbles - Tabbles use tags to organize and find files along with your colleagues.