ClockworkMod's Koush releases new cloud app backup/sync service with Carbon
Right now, the app does require a rooted Android 4.0+ device, but the final version will not require root. Basically, Carbon will allow you to backup and restore apps to local storage, cloud storage (Google Drive or Dropbox), or between devices. What's even more impressive is that when syncing an app from another device, Carbon will pull the live data from that device so you know what apps are installed, and you get the most up-to-date versions.
The beta that has been released will only work for one week before it will get shut down (and likely a new version will come out). Koush has considered the idea of open-sourcing the code for Carbon, but hasn't made a decision on that. If you want to see the app in action, there's a video in the original Google+ post, which we can't embed, because it comes up as private anywhere but that original post.