Excuse my ignorance, since I haven't JBed yet, but does it say this somewhere in a link, since so many people seem to keep making the same mistake that you say?
Edit: Great I ask a question for once and get nothing!!![]()
Sorry to be over a month late, but I saw this and didn't wanna leave you hanging .aggie. Officially Apple states that you can use the application immediately after downloading ( See Bottom Right side of page under "Download apps." ). Yet I have been told by Geniuses ( Apple, not real Geniuses ) that it increases the stability of the OS if you restart the iPhone after every download.