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.
Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).
Time Buddy - Time Buddy brings a colorful world clock.
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.
Time Zones Converter - Time Zones Converter is an application which as the name implies, is used for converting time zones.
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 .
Time Zone Converter - Time Zone Converter is an online productivity tool to calculate exact time across time zones.