Keylogger software is used to monitor each and every step (or touch), which is done on the smartphone – in this case – iPhone. From messages to the codes, passwords, and all kinds of other private, as well as public things. When someone on the phone installs this software there is no chance that you will miss any event that is done on keylogged phone. If you are not enough satisfied with classic spies for phones, this is an option that will not let you down. But of course nothing is not nearly as easy as it is when an ordinary apps needs to be installed. It is also more complicated that installing apps that will observe other applications.