More than most categories, choosing the best music subscription app involves a high degree of subjectivity. The offerings by the top competitors each bring something different to the table. Some have bigger music catalogs; others are better at sharing; still others have the advantage in terms of music discovery. Services with the most dynamic features may not have the most user-friendly interface. Non-iOS considerations also come into play, as some of the services can stream on third party devices (such as Roku, Sonos, or Boxee), or in your car. Then, of course, are the cost considerations. Ultimately, the best music subscription service for you will depend on your personal preferences. This AppGuide merely highlights some things to look out for.