to make an app in itunes, first go into options and select the start and stop time for the song. then save the changes, and exit the options screen. after that right click, or control click depending if you have mac or winodws, and click create AAC version. after you create the AAC version, click and drag it to your desktop, then after it is on your desktop, delete the copy in itunes. it doesnt matter if you remove the file from your hard drive when you select delete, as the desktop file will stay there. then go to the desktop file, and edit the file name from song.m4a to song.m4r. accept the changes even if it says that the file may be unusable after. then click and drag it back into itunes. it wil be under ringtones. then click and drag to sync to your phone or do whatever you have to do to sync it to your phone and your all set!