The extremely popular document sync/sharing service Dropbox has released its awaited iPhone application into the App Store for free.

The app also interestingly requires iPhone OS 3.1, and offers users quite a bit of on-the-go access to accounts and syncing content while on the move.

App features from the app listing:

* Access your Dropbox on the go
* View your files
* Download files for offline viewing
* Take photos and videos and sync them to your Dropbox
* Share links to files in your Dropbox
* Photo galleries
* Sync downloaded files so they’re up-to-date

Dropbox has 3 levels or ‘tiers’ of service, each with increasing amounts of space: Basic (2 GB, Free), Pro 50 (50 GB, $9.99/month), and Pro 100 (100 GB, $19.99/month). We anticipate 2GB to be plenty for many average people.