Below is how to open activity monitor in mac with software you can try.
The Monity widget lets you see a range of system information from the Notification center. Having a watch on your systems and network with easy configurations.
CPU load average, Uptime, Processes, CPU Usage.
Free memory, Wired, active and inactive.
Supports new Memory display format.
How to open activity monitor in mac with software Monity
Monitoring of all active networks.
Incoming & Outgoing Traffic (current & overall).
Copy IP to Clipboards or open in your Browser.
Charging in Watt.
Battery charge of Keyboard and Wireless Mouse.
Fan speed, Heat & sensors.
Detailed statistics for Power and Heat consumption by numerous sensors.
Information about current revolution per minute (rpm) for integral fan, in addition to their boundaries.
Widget Settings with specific customization options.
Organize and sort panels through numerous websites.
Show / Hide Panels.