Apple's interpretation of the interface using icons and the grid that iOS has in OS X is sometimes useful to keep our applications organized by folders and more easily access them having them better located, but as with many other options, sometimes it does not show all the installed applications so we will have to "refresh" the application.
The bad part is that Apple does not offer configuration options for this application either in the system preferences or within the application itself, so if something goes wrong we don't have tools a priori in order to solve it.
To try to solve this problem we have two options, one of them goes through relocate the affected app which is not showing and the second would be to force Launchpad to rebuild its database so that it correctly locates all applications.
Default location
Unfortunately, the Launchpad will only show those applications that are found within the root folder of the system dedicated to it, that is, the applications folder, so we must move said program within it. If, on the other hand, we move it inside the folder but it still does not show it, we can try to copy it again inside the folder (replace it), close the session and reboot with our user.
Confidential Information
The integration of this application is done with the OS X Dock, that is, it is part of it, so if any of the two databases that handle the applications that are going to be displayed becomes corrupted, it will cause not all the applications that we have to be displayed in the Launchpad. To force the Dock to rebuild these databases, we will go to the desktop and with the ALT key pressed we will move to the go menu (top left) to enter the Library.
Once inside we will look for this route Application Support> Dock and we will erase everything that is inside, when we have done it we will only have to close and re-open the session so that the Lauchpad will repopulate itself with applications completely from scratch.
More information - Optimize your time when copying files in OSX