Being a bit of command line geek, I often use Apple’s Spotlight feature to run applications. Its much quicker to click the command key and spacebar then quickly type what you want then to use the trackpad or mouse to find the application.
Sometimes though, the index can get corrupt and spotlight stops finding some apps. Its a quick fix and very easy.
First find your way to /Users/(loginname)/Library/Preferences, the fast way to do this is from finder press Shift-Command-G then type ~/Library/Preferences this will take you to your library within your user folder. Its easier this way as the library folder under your user is hidden by default.
Find com.apple.spotlight.plist and delete it, then as an administrator run terminal and enable Spotlight Indexing by typing mdutil -E / you may have to use sudo (super do) as its requires admin permissions.
This should then sort out your spotlight issues.