Cellular connection kicks in when the WiFi is weak, that's a nice feature in iOS 9: WiFi Assist.
I have on question, when WiFi Assist is ON. Does it cause me cellular data in the following scenario:
- WiFi Assist is ON
- Settings > App and iTunes Stores > Use Mobile Data is OFF
- Now, WiFi is good
- I am downloading a huge app
- ... so far so good
- suddenly WiFi goes weak ..
Does AppStore continues to download and consumes my cellular data, or just stops?