In case you are interested in monitoring the whole conversations that happen on the mobile phone of a person, you have to go and check the flexispyreview.org website. But tracking the SMS is not the only thing that this program does. It is capable of much more.
The program is proficient at interception the phone calls at the moment they happen. Also, the phone can be turned into sort of a bug. It can be used in order to listen to the surroundings. It is also possible to record the audio. You have to make sure that these functions are legally used as not to get into trouble.