I forgot about that. It was a Palm developed software that they also ported to Newton. Well they are long dead now. I forget who bought them, but they have clearly moved on if they aren’t dead too.
It was a bit convoluted. USRobotics bought Palm, was bought by 3Comm who later spun off Palm. The original Palm founders later started Handspring, which used PalmOS. They later merged with Palm, and eventually HP bought them and destroyed Palm. It was a shame, because they really were good devices that could be today what the iPhone/IPad are.