What HDDlife can and cannot do.

HDDlife can …

let you know when storing data on your hard drive becomes dangerous. Thus, you have enough time (usually, 1 or 2 days at least) to back up your personal data and replace your hard drive with a new one.

HDDlife cannot…

prevent loss of data in the case of force majeur. HDDlife neither backs up nor copies data in any other way, it just analyzes the condition of your hard drives. HDDlife cannot forecast such possibilities as a breakdown due to a surge in voltage or even the drive itself being dropped.

S.M.A.R.T. technology only protects against hardware failures, but not against software errors.
For example, if the drive had mysteriously turned to RAW file system, but is still good mechanically, you need a data recovery soft.