KumoApps are supposed to allow defining triggers that use location of iPhones and iPads (http://mytaglist.com/kumoapp/19/region), such as "Arm motion sensors when all phones are away from home, disarm when any enters near home." and "Turn off AC/heat when all devices exit a region". However due to bug in the iOS app, this did not really work at all until now.

We are pleased to announce that with the latest iOS app release, these KumoApp will start to work. When you stop and restart the KumoApp, the holder of each device you have chosen will receive a push message that asks for permission to start monitoring region for the KumoApp. The holder would tap on the notification to open the app to start monitoring the region configured with the KumoApp. Once monitoring is started, even if the iOS app is closed, KumoApp will be triggered upon entry and exit of the specified region.

There are still several known issues which will be fixed in the next release:

• If you receive "error start monitoring region, kCLErrorDomain error 4", you need to go to home screen, open the "Settings" app and then "General" then "Background app refresh" and disable and re-enable the toggle switch next to "Kumostat" app.
• Sometimes you will receive "error start monitoring region, kCLErrorDomain error 5". This error can be safely ignored.

Try linking your Nest Thermostat and install the "Turn off AC/heat when all devices exit a region" today.