Since upgrading to iOS 9 on my iPhone 6 and iPad air, both are downloading tons of data in the background for apparent reason. This isn't the wifi assist issue - I'm not talking about 4G data. It's the data they're pulling down over wifi. Why this is an issue: I live in South Africa, and my home wifi data is capped at 30Gb / month. These have wiped out several gigabytes without me even noticing. If I forget to turn off the wifi on one of the devices, I'm in trouble. What I've tried: I've been tracking things closely. It happens inconsistently, but often enough that I can watch it by watching the data statistics on my router. I've tried turning off the Background App Refresh. It still happens. It's hard to google, because the wifi assist issue is always what comes up. Can anyone help me?