What country are you in? The device selection does vary. While TRVs are more popular in the EU, they do exist in the US, but have quite different specifications. 
Also, in most cases, a TRV is a thermostat for that specific room, rather than for the central boiler. It has its own temperature sensor and controls the radiator valve that it attaches to. So I’m a little confused about what you’re looking for.
If you just want a smart thermostat for a central boiler, there are quite a few of those, but again it depends on the country you are in.
If you want a smart TRV that controls the valve setting on an individual radiator in an individual room based on the temperature in that room, those also exist, but they are a different device class.
If you want a system that combines both, there are a couple of those, but it’s more than just a boiler connection: you need to add the TRV to each individual radiator that you want to control.
In any case, here’s a recent discussion that might be of interest. Again, note that the country does matter.
Smart Thermostatic Radiator Valves TRV with Edge driver? (EU)