Tizen is a proprietary operating system of Samsung. For the digital signage displays of Samsung you can find it in versions 4 until version 8. The odd thing is that Samsung doesn’t use this operating system over other products of them (i.e. smartphones, tablets, smart watches), so the future of this operating system is unclear.
However, in some places in the world, smart displays (also called “SoC”, which means System-On-Chip) of Samsung (which are Tizen operating system based) are the only option for getting smart displays.
NoviSign has a web-based app running on Tizen operating system. This app was specifically adjusted to Samsung Tizen.