The Application Dashboard is easy to navigate through the installed apps because it put the apps in the categories automatically. However, there are some apps we do not want them to appear. They maybe the dependencies of other applications and we rarely open them.
In the following screenshot, you can see several mystery icons like Contact Print Theme Editor Contact Theme Editor KMail Header Theme Editor KTnef PIM Setting Exporter. They are pretty annoying to me. Seriously? Who needs to edit their “contact print theme” every day?
In KDE plasma, the shortcuts are located at either /usr/share/applications/ or /home/foo/.local/share/applications/
Open the *.desktop file of the app you want to hide. Add NoDisplay=true at the end of the file.
Done.