Neither Google nor ConvertAll know about Scruples. Both are convenient ways to convert units. The unix console utility (non-GUI) Units is my choice, so far, as it knows at least one unit, about which the two flashy tools do not.
I installed ConvertAll through Synaptic on Ubuntu. It is written in python using the QT library, so it is usable on Windoze as well as GNU/Linux systems. It's a GUI solution. It doesn't know about scruples, but it is claimed to work well with composite units, such as Kg/m/hr
In the google search bar, I enter "2 scruples in g". Google doesn't know about scruples either.
Units wins the first round. And it's easy to use.