BuildCleaner
http://www.davedelong.com/downloads
A simple app that searches for old and unused Xcode build folders and deletes them. A couple options are available, including the ability to ignore build folders for specific projects and the cutoff interval for deleting folders.
起動するとメニューバーに常駐します。
削除処理の周期が設定できます。
ダウンロードはこちらから。
http://www.davedelong.com/downloads