also if u have an older os you are limited to a certain # of apps on home screens so it would only be in spotlight. or try deleting it and redownloading it or shut it off and back on. but like the guy guy before me thought it might be in a folder.
a really, really low chance but do you have sbsettings installed? if so, did you maybe enter the turn off icon screen and accidentally swipe that one on, er, off as the case may be?