System Activity Monitor

Activity Monitor11.5

Monitors activity on the computer to detect viruses and misuse

PRO: Very complete: controls pretty much everything
CON: A client app needs to be installed on each PC you want to control
Vote: 6.3/10 (100 votes) Platform: Windows

Simple System Monitor3.6.24

Simple system monitoring tool

… frequency to keeping an eye on your battery temperature, as well as network activity, Simple System Monitor

Vote: 4.5/5 (57 votes) Platform: Android

Microsoft Process Monitor2.95

Track all the activity in your Windows file system and registry in this free download

PRO: Many tools to manage system processes
CON: Not for novice users
Vote: 4.2/10 (8 votes) Platform: Windows

HomeGuard Activity Monitor12.0

Monitor every aspect of the home while away

PRO: Keylogger
CON: no free version
Vote: 9.2/10 (329 votes) Platform: Windows

Desktop Activity Recorder2.00

A security program designed to monitor and record keystrokes and program usage

PRO: Simple to use
CON: Doesn't allow much sound editing
Vote: 6.4/10 (97 votes) Platform: Windows

MKN TaskExplorer5.0

Monitors activity online and manages tasks that are completed

PRO: Extended information about each process
CON: Basic documentation
Vote: 6.2/10 (23 votes) Platform: Windows

System Monitor II31.5

A program for Windows that monitors a variety of system processes and displays device information 

Vote: 5.5/10 (18 votes) Platform: Windows

System Monitor Lite1.5.2

Most complete and beautiful System Monitor!

Vote: 4.5/5 (41 votes) Platform: Android

System Info Monitor1.2

Check your entire system with one single tap, with System Info Monitor Manager!

Vote: 4.0/5 (102 votes) Platform: Android

All-In-One Keylogger5

Monitor your keyboard activity with this software

PRO: Secure encryption
CON: Not yet localised for all regions
Vote: 7.1/10 (79 votes) Platform: Windows