MacMetra

MacMetra is a system monitor that lives entirely in the macOS menu bar. There is no Dock icon and no main window: the menu bar item is not a shortcut to the app, it is the app.

One compact item shows up to three readings — CPU load, thermal state and memory — and you choose which of the three appear and in what order. Clicking it opens a panel with cards for CPU (total load as a ring, split into user, system and idle), memory (used and free, plus the memory pressure the system reports), storage, thermal state, and power (charging state, charge level, time to a full charge, and whether Low Power Mode is on). Readings refresh up to twice a second at an interval you pick, and sampling stops while the displays are asleep.

Worth knowing before you try it: MacMetra stays inside the App Sandbox and installs no helper tool, so it reports the four-step thermal state macOS itself publishes rather than named sensors in degrees, and it does not show fan speeds. Reading those requires access the sandbox does not grant.

It has no network access, no accounts, no analytics and no telemetry, and it keeps no history — readings exist while they are on screen and are then gone. Written in Swift and SwiftUI, universal binary, macOS 14 or later.

Free to download, with every feature free for seven days, then a one-time unlock rather than a subscription.