Only Apps inside of /Applications
and ~/Applications
are displayed in Launchpad. When you launch from Xcode the apps are copied to a temporary build directory. So you have to copy your app to the correct location.
If you only want the Debug version, because you want to test your app, you can simply locate the app bundle in Finder:
Open the Products
group in Xcode, right click the .app file and select "Show in Finder". In Finder simply drag & drop the app into the Applications
folder.

If you need the Release version you can archive the app. Select Product/Archive in the Xcode menu.

In the Organizer you choose Export, in the Export wizard you select "Export as Mac Application". You can directly save it into the Applications directory, or save it somewhere else and copy or move it into the Applications directory
