SMARTreporter (Donationware) is a one-trick pony, but it is a clever one-trick pony. The app monitors your hardrive using SMART technology (if the drive is SMART-compatible) and warns you if drive failure is imminent.
You can select a pop-up alert, an automatic e-mail alert, have a particular application start-up, or all three. There is also an optional Finder Menu Bar icon that turns red if the drive is failing. Since hard drive failure can be gradual in nature, an early warning that something is amiss can mean the difference between salvaging data or losing everything that isn't backed-up.
Since SMARTreporter is an application, it needs to start-up at login to monitor a drive. Automatic start-up can be set in the app's preferences or by adding it to the start-up items under System Preferences/Accounts/Login Items.
