1)
DiskCheckup 2.0
DiskCheckup measures the performance and 'health' of your S.M.A.R.T. enabled hard disk drive. It can track attribute changes over time and 'predict' the date at which your HDD will fail.It can be command line driven and will also send alerts by email 2)
SIGuardian Lite 1.6
Save your data! SIGuardian Lite estimate hard drive failure BEFORE it really happens. SIGuardian Lite work with all modern hard disk drives. Prevent your data loss before it really happens for cost only $15! 3)
SIGuardian 1.7.335
Save you data before HDD failure destroys it. SIGuardian uses S.M.A.R.T technology to accurately predict the date when a hard-drive is no longer safe to use. This tool is also capable of monitoring HDD temperature and alerting you over the network.