Stellar Drive Monitor is described as 'brings in good news for Mac users having OS X 10.4.11 to 10.8, now each of them can closely monitor the internal hard drive activities & corresponding partitions in the most simple fashion' and is an app in the OS & Utilities category. There are seven alternatives to Stellar Drive Monitor for Mac, Windows, Linux, BSD and MS-DOS. The best alternative is GSmartControl, which is both free and Open Source. Other great apps like Stellar Drive Monitor are smartmontools (Free, Open Source), DriveDx (Paid), StableBit Scanner (Paid) and Data Lifeguard Diagnostic (Free).
The smartmontools package contains two utility programs (smartctl and smartd) to control and monitor storage systems using the Self-Monitoring, Analysis and Reporting Technology System (SMART) built into most modern ATA and SCSI harddisks.
StableBit Scanner is a state of the art disk health monitoring tool. - Monitors the SMART data of your disks, and presents them in an easy to read, meaningful way. - Lists detailed information about your disk, including the connection type, bus speed, and supported features.
This is a Windows version of the Data LifeGuard Diagnostics. It will test WD internal and external drives. In additional, it can provide you with the model and serial of WD drives attached to the system.
Diskscan is intended to provide the information needed to decide if a disk is good or not, be it an HDD or an SSD it is likely to be holding important data and if you have a suspicion that it is failing it is also important to know how bad is it down the road.