To download mp3 (audio): Click "Download mp3" button
To Cut/Crop mp3: Please use the slider below and click on "Download mp3" button to download the selected part.
Note that video to mp3 conversion output is limited to 10 minutes.
Basically The "SideLoad" Means Installing Apps or game for windows phone form a source other than the market place.
so if you need to Use this tool to sideload Xap's to your windows phone 8 or 8.1 device , you need to jailbreak Your Windows Phone First ( Jailbreak is also non as developer unlock,)