After a few years I still use Listary as my main search/launcher. It's very quick, has a very nice look and great system of filters and projects. There are problem with new version to be released, but I'm talking about version number 5.
j4-dmenu-desktop - A replacement for i3-dmenu-desktop Its purpose is to find .desktop files and offer you a menu to start an application using dmenu.
Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).
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.
Wox - An effective launcher for windows. A full-featured launcher, access programs and web contents as you type. Be more productive ever since. Wox is free for use and open-sourced at Github, Try it now! Download .
Pixie - Pixie is a free, open source web application that will help you quickly create your own website. Many people refer to this type of software as a content management system (cms), we prefer to call it a small, simple, website maker.
Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.