iStatistica is described as 'advanced system monitor for macOS and iOS. It includes notification center widget and menu bar popover / monitoring dashboard. Simply slide out notification center to keep an eye on your CPU, memory, disk usage, network activity, sensors and fans data' and is an app in the OS & Utilities category. There are five alternatives to iStatistica for Mac and iPhone. The best alternative is iStat Menus. It's not free, so if you're looking for a free alternative, you could try Stats Panel or Beaconly. Other great apps like iStatistica are Hologram Desktop (Paid) and Pluto HUD (Paid).
iStat is a series of system monitor apps. It's available in different versions: iStat Menus, iStat for iOS and iStat Server as a companion application to the iStat for iOS app that lets you remotely monitor your computers (free for Windows and Mac).
Beaconly is a flexible, easy to use data aggregating menu app that ties relevant information to you, beautifully one click-away in your macOs menu bar. Easily discover status of AWS, your Jira Tickets, and so much more.