Fuel Level

From the App Store Source

Just like checking the fuel left in a tank, a glance at the needle tells you how much memory headroom your Mac has right now. It's made for watching the dial, not for reading exact numberFuel Level is a small menu bar app that shows your Mac's available memory as a car fuel gauge. Just like checking the fuel left in a tank, a glance at the needle tells you how much memory headroom your Mac has right now. It's made for watching the dial, not for reading exact numbers. This app traces its roots back to 1995, to a Classic Mac OS app of the same name. Back when memory was tight, it showed free memory as a fuel gauge — and now it has been redrawn from scratch in SwiftUI for the modern Mac. The needle, the dial face, and the warning lamp are all drawn in code. Features: - Shows available memory with a needle straight out of a car's fuel gauge - A warning lamp lights up as memory gets tight, and blinks when it gets critical (tied to macOS memory pressure) - On launch and on wake from sleep, the needle sweeps like a car's ignition self-test, with the warning lamp briefly lighting up - Two dial shapes: Comfort (flat-bottomed) or Sport (a full circle) - The System Monitor (hidden by default) plots CPU usage over time as dots, styled after a car instrument panel - Click the System Monitor to switch between the graph and figures: fixed-width digits show free memory, memory pressure and CPU, broken down into user and system time - Turn on Quick Reveal and a moment's rest of the pointer at the bottom edge of the screen brings every hidden gauge to the front at once - While the gauges are revealed, hold down Shift to see the System Monitor's numeric readout for as long as you hold it - Three display modes: a normal window, always on top, or pinned to the wallpaper - Appearance: Auto / Day / Night, with an amber instrument glow at night - The needle is tuned to avoid flickering on tiny fluctuations, so it stays calm to watch - Remembers its position per display on multi-monitor setups - Japanese / English UI - Lightweight: the static dial is never redrawn — only the needle moves - The app makes no network connections of its own Just a needle swaying quietly in the corner of your desk makes your Mac a little more enjoyable.

Every number in these answers comes from the data shown above on this page.