The free IceTV app can be found listed as "IceTV - TV Guide" in the iTunes store in the iPhone section.
Just visit the iTunes store on your iPhone, iPad or 'iPod Touch' and make sure that 'iPhone' is selected at the top. The iPhone version works on iPads but is only listed in the iPhone section as we don't yet have a separate iPad version. With 'iPhone' selected just search for icetv
If you are reading this on your iPhone, iPad or iPod Touch you can tap here.