CrashPlan 4.6

Only CrashPlan offers local and online backup that's automatic, secure and cross-platform. Whether you need to back up one laptop at home or up to 10 for the family, CrashPlan delivers multi-destination protection that maximizes convenience, flexibility and rapid restores.

It's free to back up locally and to friends and family, and it's just a few dollars a month for unlimited online backup with a CrashPlan Central subscription. Unlimited online backup.
There is also a mobile app for users with a CrashPlan+ account. Mobile users can securely access data backed up to CrashPlan Central onto iOS, Andriod and Windows Phone devices.