Last night I was working on a script to build and sign iOS applications for ad hoc distribution. If you've ever done over-the-air distribution of iOS applications, then you have probably seen what happens when you attempt to install an application that is not signed properly. The installation will start and progress to a certain point and then fail and then re-try forever or until you interrupt it. What I discovered last night is that even when you interrupt it, it may still continue looping in the background.
It got late and I got tired and I decided that I'd stop and go to bed. I held my finger down on the icon until it got shaky and then hit the X. It kept going. So I did it again and it disappeared and I went to bed. About 10 minutes later, my wife, who was watching a movie on her iPad, says, "What happened to the WIFI?"
I looked and found that my WIFI had indeed become unavailable, so I reset my cable box and the wireless access point and got everything back in order and went to sleep.
At around 4:30, I woke up because I heard a buzz and the room lit up. I looked at my phone and I had 23 text messages from AT&T letting me know that I had exceeded my allotted 5GB of monthly data. I looked at my cellular usage and found that I had used a total of 20.5 GB! Unfortunately I slept through the first 22 messages.
I went to my computer and took a look at the server logs on the remote system from which I was serving the bad .IPA file and found that my phone had tried every 3-5 seconds to install that app since I stopped working on it the night before. My phone apparently never switched back from LTE to WIFI after I reset the access point around 5 hours before.
Since I get charged $10 for every GB that they add, my phone bill will cost an extra $150 next month.
So I would recommend that if you ever see an app in an install failure cycle on a device with cellular connectivity, you may want to power-cycle your it just to make sure that it was terminated. I'll be using my WIFI only iPad when I resume working on this script.