Iphone 6s software size is 18 GB
Is it normal that software size in my Iphone6s is 18 GB. It seems to slow down my phone ! I have the latest IOS.
No. There is something wrong. Mine is around 4 GB.
Try a forced restart which is to press and hold the Sleep/Wake and Home buttons together until the Apple logo appears.
http://www.idownloadblog.com/2015/10/27/how-to-remove-software-update-download-p hone-ipad/