Almost all iPhone or iPod touch users have downloaded a free app, but 82 percent have actually made a music purchase from iTunes, according to a new survey from NPD.

More than half (56%) of iTunes buyers purchase music exclusively, and majority of iTunes user search time is focused on looking for music.

“Sales growth in digital music has been slowing, and some of that decline might be related to the distraction from apps; however, iTunes shoppers are still completely engaged with music, whether it’s about listening, discovering or buying,” said Russ Crupnick, vice president and senior entertainment analyst for The NPD Group.

“Apps and video certainly do compete for consumer dollars, but they can also be used to promote music and re-energize digital music and video download sales.”

The report also looked at the question if apps are valuable to users or mostly frivolous. Two out of three iPhone and iPod touch owners who have downloaded apps report using them regularly, instead of just using them briefly.  In addition, nine out of 10 have downloaded a free app, which Crupnick says, “points to a major up-selling opportunity to paid versions of the same app.” Plus 69 percent of iPhone and iPod Touch owners who have not yet paid for an app told NPD they are interested in possibly doing so in the future.