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It is normal that the folder is called simple. The folder name actually doesn’t matter, you could even rename it to whatever you want. More important is the name you provide in your package.js file.
As @shock already pointed out, the name has to be in the format username:package-name, and package-name does not have to match the folder’s name (though it makes much sense to keep both the same).
The most important thing you were missing is to add the package via meteor add. It is not sufficient to just create the package, it also has to be registered with your application.
Besides this, please also note that you are using the old syntax api.on_use and api.add_files in your first sample. The new syntax is api.onUse and api.addFiles, although both variants are still supported.
It seems as if you’ve taken your first samples from a quite old tutorial.