Cerebro is very simple to use and has minimum settings, after starting integrates in the notification area (system tray), supports the change skins Windows startup (there is a light and dark theme).
Using Cerebro, you can do different actions using only the keyboard, called the keyboard specified by a combination of window it is enough to type a few characters and receive a list of "similar" applications to run a web search (Google, DuckDuckGo! etc), open the directory on the file system (with preview of file), you can use the tool as a calculator, currency Converter and more...
Cerebro consumes minimum system resources and is a NetWM / EWMH compliant application (does not depend on any desktop environment).
Installation latest version into Linux Mint:
May the Force be with you,