How can I create an entry in the /Applications folder that runs a command in the terminal?
Use Automator which Apple made part of OSX..

Create a workflow

In the workflow choose Utilities/Run Shell Script

Save as changing the File format to application - this will give a .app and choose the directory to be /Applications

EDIT to show the output.
The workflow need sto consist of three steps

1) Text->Create New TextEdit Document
2) The Utilities/Run Shell Script
3) Text->Set Contents of Textedit Document