Code 42 Software has released, a free iOS app that lets you access your CrashPlan Central backups with any iOS device. (A separate version for  devices is also available.) If you back up your files in the way the app assumes, the effect can be almost magical: near-instant access to any backed-up file, from any of your computers that use CrashPlan, no matter where you are — and even if the computer itself is offline. I tested the app on my iPhone and iPad and it worked as advertised; I find it a highly useful addition to my existing methods for accessing data remotely.
This being version 1.0, CrashPlan Mobile lacks some important features many people would like to see, so you should set your expectations accordingly. (We understand that the company is hoping to add at least some of these features to future versions.)
This app is for CrashPlan+ users who back up their computers to CrashPlan Central, not for those who use only local or peer-to-peer backups.
It works only if you secure your backups with your account password (the default method); if you use a private password or private key for greater security, the app does you no good at present. (This should be obvious, but since your account password protects all your backed-up data, make sure it’s a strong password!)
You can access only the most recent versions of backed up files; older versions, or files that were deleted from your computer before your most recent backup, don’t show up in the app.
Although you can download any file and view common file formats such as text, PDF, and graphics, some data formats (including audio and video) can’t be viewed within CrashPlan Mobile.
The app is only a one-way conduit; it doesn’t let you back up files from your iOS device to CrashPlan Central.
Even with these limitations, though, it’s hard to complain. After all, CrashPlan Mobile is free, and it adds a powerful capability to my favorite online backup system. With time, it’s bound to become more useful still.