Clementine - Clementine is a cross-platform free and open source music player and library organizer based on...
CopyTrans Manager - CopyTrans Manager: The free iTunes alternative to manage iPhone, iPad and iPod without iTunes. CopyTrans Manager allows you to quickly drag and drop music and videos from PC directly to your iPhone, iPod or iPad.
MusicBee - While iTunes might be the benchmark music organizer and player app, MusicBee is a strong alternative that many prefer.
iMazing - iMazing lets you transfer music, files, messages, apps and more from any iPhone, iPad, or iPod to a computer, Mac or PC. Manage and backup your iOS device simply without iTunes. (was DiskAid)
Droid Transfer - Save and Print your Android Phone Messages, Manage Photos, Music and other files on your Android Phone through your PC. Android Transfer Software.
iExplorer - iExplorer lets you easily transfer music, playlists, text messages, files and more from any iPhone, iPod, or iPad to a Mac or Windows computer and iTunes.