Last week we talked about TubePod a free YouTube video converter for Mac, this week we are introducing you with another free and useful application for MacBoys. Tagr is an application for Mac OS X that helps you organize your MP3 / M4A (MP4) collection. Who editing the ID3 tags of his music library on iTunes very frequently, should the Mac Freeware Tagr allow a test run. ID3 is a metadata container most often used in conjunction with the MP3 audio file format. It allows information such as the title, artist, album, track number, and other information about the file to be stored in the file itself.