iphone5sBesides SMS Messages one can find iMessages on an iPHone, iPod or iPad. iMessages seems to be the same as SMS Messages for most people, but they aint.
SMS Messages are sent trough the telephone network, while iMessages are sent trough the internet. For iMessages one always need an internet connection.
Just like SMS Messages, iMessages often can be retrieved from mobile devices. To retrieve them you need specialised hard- and software. Digirec uses the Cellebrite UFED Touch to achieve this goal.

We also use Encase, the number one forensic software for data-investigations in the world for our investigations.