I installed Tasker recently which I set to automatically change my wallpaper every 10 minutes and soon after noticed my data usage shoot up. It seems my phone has been backuping my wallpaper at every change and used up 400MB of my monthly data allowance.
Turned it off and it's back to normal now. Also noticed if I manually change get the wallpaper the data usage (by Android OS) goes up by about 2.5MB.
How much data do you have per month? And how much do you pay?
I've got 1.5GB with T-Mobile. Can't change anything for another year or so.
"Android OS" also used 620MB when WiFi connected. That's a lot of wallpaper backups.
oh blimey mine's doing daily wallpaper changes with the "Pattrn" app, never thought of backup. Hahaha.
Hmm, they seem to not be making much difference to usage though, probably small images. I had the NASA app doing this before as well though with photos and never noticed a problem.
The data usage graph is quite flat until the date I installed Tasker and suddenly starts rising quickly.
Doing a bit of quick testing and it might be Android backing up Nova Launcher or its settings. I've changed to TouchWiz, enabled Tasker and still normal.
Maybe I spoke too soon. Just gone up by another 2MB.