/usr/share/applications and find the .desktop file for your application. (It will probably be displayed as just an icon if you use a file manager to do this. Part of mine looks like this, but the files are really called [something].desktop)
Copy it into
Open the .desktop file with your favorite text editor and look for the line starting with
Change this line so it reads
Categories=Development; and save the file.
Your menu may refresh immediately; if it doesn't, open a terminal and type