Cloudbeats is the only one iOS app so far which allows streaming of audio files from Dropbox, Google Drive, Box, OneDrive, Mediafire, ownCloud.
You save a lot of mobile storage space on your mobile device by storing audio files such as flac / mp3 in the cloud (see my blog post). Then you can hear your music by multiple devices on all operating systems. For iOS the cloudbeats app is needed which does a nice job. Chromebooks can read it nativly, for windows and mac there are many players available.
I use it to enjoy lossless sound in the office / bed or other areas with WIFI access (the app can copy files for offline usage though) from my library on my gdrive. No need to sync files anymore.
You can get cloudbeats from the Apple app store.