Battery Indicator for 3rd Party Devices?

So I have been busy working on remote desktop solutions and one of the things that I am going to need to address is piping in the actual battery drain of the device which I am working off of. It is possible that I am booted into either Linux, Windows or macOS - regardless I want to setup a new battery indicator app that has an API of some kind to accept the battery level(s) of other devices.

I assume there is nothing like this in the Linux ecosystem, any advice or pointing of directions would be greatly appreciated to help get me started.

This is the sorta thing I would like to bring to both Linux & Windows.

Of course getting the battery drain from iOS devices directly I suspect will be impossible, but if these apps can get it into macOS then there may be indirect ways of pulling in Apple Watches and iOS devices too. I think this would also make the setup of using an iPad or iPad Pro device for serious work much more tenable.

Is there anything here that helps you with your project?