macOS doesn't make it easy to see how much juice is left in your AirPods, Magic Mouse, MX keyboard, PS5 controller, or any other Bluetooth peripheral. Some of it is buried in System Settings → Bluetooth, some of it never shows up at all, and most of the third-party tools that fix this are paid or come with analytics baked in. I wanted a tiny free thing that just worked, so I built MacJuiceMonitor. A small Electron app that lives in the macOS menu bar and polls every connected Bluetooth device for its current battery percentage. AirPods, headphones, mice, keyboards, game controllers — anything that reports battery — shows up in a single dropdown, with the percentage right next to each device's name. You can also pick one device whose battery the tray icon itself mirrors, so the number you actually care about (usually the AirPods, in my case) is visible at a glance without opening anything. Electron + TypeScript with electron-vite for the build pipeline Polls macOS through system_profiler SPBluetoothDataType and parses the connected-devices section every few seconds Renderer rebuilds the tray menu template from the latest snapshot on every tick No analytics, no auto-update phoning home, no paywall. Clone, yarn build, ship to /Applications, done. Electron tray menus flicker if you try to edit individual items in place every poll. The fix that actually works is the opposite of what feels efficient: rebuild the entire menu template every tick and assign the whole thing at once. macOS handles the swap atomically and there's zero visible flicker. The code looks wasteful, but the UX is buttery — and it's the same pattern other macOS menu-bar Electron tools use once you dig in. MacJuiceMonitor on GitHub plain url for crawlers: https://github.com/p32929/mac-juice-monitor honest takes / stars / forks all welcome if it's useful. PRs especially — there are device types it doesn't recognise yet that someone with that hardware could add in 10 minutes. open to building with sharp teams + solo founders — dms/email open.