Better Resource Monitor puts macOS stats in the menu bar
Processor. Memory. Network. GPU in the menu bar, no extra windows, no root helper.
What it shows
Four metrics in the menu bar, each individually hideable from the menu. On Apple Silicon it stays under 0.1% CPU and around 15 MB of memory. Binary is under 7 MB.
Better Resource Monitor: free, under 0.1% CPU, around 15 MB of memory, public GPU API, no root privileges (sandboxed).
iStat Menus: $14.99, around 1% CPU, 100+ MB of memory, proprietary GPU API, requires a root helper.
Stats: free, around 1% CPU, around 50 MB of memory, private GPU API, requires a root helper.
How it works
Rust and Tauri. CPU, memory, and network come from the sysinfo crate. GPU activity on Apple Silicon comes through IOAccelerator (public IOKit, no private API, no root helper). Sandboxed and ships on the Mac App Store with GPU monitoring still enabled.
No analytics, no telemetry. Open source under the MIT license.