The setting to enable or disable Background App Refresh is applicable for both WiFi and cellular. There is no way to disable it only for cellular data. So yes, apps that use location services can drain your cellular data plan.
Possible solutions:
- Restrict which apps are allowed to use background refresh. You can thus limit the amount of data usage by turning on this setting only for the apps that you need background refreshes for.
- Turn off cellular data for specific apps from Settings->Cellular (this page also shows the cellular data used by your apps). This would completely restrict those apps only to WiFi all the time though.
There are two types of update.
OS X software updates are updates for the OS and OS components (e.g. iTunes). These used to be delivered through a separate software update app, but since the introduction of the Mac App Store, the OS X updates have been combined with Mac App Store updates in the Updates tab of the Mac App Store. However, the CLI tool remains, giving you more flexibility in Terminal and allow the downloading of updates without installing them, perfect for copying to other machines before the installation takes place.
You can download OS X updates without installing them (which would automatically remove them) so you can copy them, using the following command:
softwareupdate -dav
The 10.9.4 update is distributed externally, outside of the Mac App Store; the Mac App Store just provides the UI for the installation process.
Conversely, for Mac App Store apps, you need OS X Server's Caching service, as the apps are 'non-transferrable' and the app receipt must match the Apple ID that downloaded the app for the app to be updated in the future. However, if you're using the same Apple ID, or don't care about updating the app from the second machine, update the app normally then copy the .app bundle from /Applications to the other Macs as necessary.
Best Answer
Background app refreshing is just checking for new content and updating it in the app while the app is running in the background. I've never heard of an app actually updating itself and calling it a background refresh, and if it did that would certainly be a case of the developers mistaking the meaning of 'background refresh'.
Automatic updating is usually a separate setting (either in the app's preferences or the app store, depending upon which app you are talking about).