We are using it for our LoRaWAN application we are building in Calgary. SensorThings API is a new standard but I expect to see very quick adoption. I know there are four to five different groups around the world implementing SensorThings API server at the moment. If you are interested in using it, contact SensorUp (info@sensorup.com). SensorUp has the most complete and mature implementation of the SensorThings API at the moment. You can try this interactive tutorial: http://pg.sensorup.com
In fact I am the editor of the OGC SensorThings API. If you have any question, let me know.