Better Resource Monitor

Better Resource Monitor keeps a handful of system figures in the menu bar: processor and memory load, free storage, GPU use and network throughput. It deliberately leaves out fans, temperatures and sensor history, aiming instead to be a quiet, low-overhead readout you can glance at during the day. An optional setting tints the menu bar item when load or free space crosses a fixed threshold.

The project says the app is sandboxed, makes no network requests and needs no administrator helper. It is built with Rust and Tauri; the author publishes DMG builds on GitHub and the same app on the Mac App Store.