Hey guys/girls is there any way for me to stop the iphone from switching to 3g every time it goes to sleep? I turn off cellular when I am at home due to not wanting this behavior to go on, but is there any way for me to toggle cellular on only when I leave wifi hotspots (without having to go into settings all the time)? I ask because with my 4s it seems to use a lot of data and I always fully use my data each month on Verizon and don't want to pay overage fees...