Are there any apps that periodically send the battery status of one iOS device to another iOS device(or to the cloud)?
Interesting.... Let us know how you get on with the app. I'm okay with the Mac OS app for the time being but keen to hear how you're finding it.@Beards - there is an app called PowerTracker Mobile in the app store that claims to work. You have to allow notifications (I'm guessing it sends silent notifications to periodically wake up the app to check the battery). It is not a beautiful app, but it may be the answer.
I just installed it. It timestamps the data it gets from the other device and the last measurement I see was from 12 minutes ago. Personally, I'd be happy with updates on the hour, so hopefully it's at least that granular.
Shame that 'Find iPhone' does not show the actual battery reading, only a battery icon.PowerTracker Mobile is working fine.
Other options that have come up include Apple's Find My iPhone (which also reports battery status) and holding ALT and clicking Wifi in your Mac's menu bar to see the battery of devices which are eligible for tethering.