1)   Inactive Users Tracker 3.0.90
Inactive Users Tracker automates the management of inactive user accounts. The program periodically checks user accounts in specified domains, reports to you, and automatically disables all accounts inactive for more than a specified number of days.

 2)   True Last Logon 2.5.1.1
Find the true last logon time for every user and computer account. Clean up your Active Directory by easily identifying unused or obsolete user and computer accounts by identifying their true last logon time and account status.

 3)   JiJi Active Directory Cleaner 5.0
Schedule a policy for inactive users auto deletion or notification via email. You can scan your AD for inactive users, disabled users, inactive computers and disabled computers.

 4)   Inactive Users Tracker PowerShell Cmdlet
NetWrix Inactive Users Tracker is a PowerShell cmdlet that scans inactive users in Active Directory. The cmdlet obtains last logon time stamps from all DCs and outputs a list of users tha have been inactive for more than specified number of days.