Samsung has recently removed the SMART IPTV and several apps from the Samsung Stores. There was actually no official announcement as to why this is done however further investigation I found out that Samsung is planning to install more Apple TV Casting and Apple TV services and although it is unclear as this is the reason why they removed SMART IPTV from their store, Samsung TV now simple no more SMART then just a TV with Youtube, Netflix and Amazon Prime.
Some Samsung TVs now have it and some don't
Full information how you can get it back are here including download links
Video to explain the process in youtube.