MightyMonitor

Very nice! Works well with the Magic Mouse. I also like the way it looks, very sleek. Thanks!

Looks like this is now abandonware.

Unfortunately it does not seem to be working with El Capitan.

The reviews are all praising this widget, but I may be missing the point of it… MAC OSX already offers a convenient way to check the battery % remaining for any paired Apple mouse~keyboard~trackpad by 1st clicking "Show Bluetooth in menu bar" in the Bluetooth System Preference pane; thereafter, simply click on the Bluetooth menu bar item & drag down to the device you wish to check. When one of those paired Apple devices needs battery replacement, the menubar icon will begin to blink.

Handy, but the accuracy of the readout doesn't inspire confidence. Yesterday the display had dropped to 24% charge for the keyboard, and was indicated in yellow. Today, the keyboard's charge remaining has jumped up to 27% and is green. Huh?

It is good, but it's just a dashboard widget. It could have been much more useful if it was a menu bar item and had alerts. The display is a bit cheesy, but it works as advertised.

This has a nice aesthetic. Note to MagicDriver users: select "Apple Wireless" as your mouse in this widget for it to work as expected.

Very nice! Works well with the Magic Mouse. I also like the way it looks, very sleek. Thanks!

This is very useful. Anyone know how I can put this in my dock? Thank you.