Pretty well designed app for people who still have a lot of offline music (like me). It allows for both streaming and offline access. However, I'm not sure how many people use Dropbox, Drive or Mega to upload their music though. I uploaded my entire collection of music to Google Play Music and have been waiting for them to release a nice iOS app.
20 songs per service is free. To unlock unlimited songs, there is an IAP purchase. For this weekend only (according to creator), the entire app + IAP is free.
Shyp