Has anyone been requested or inquired about the use of ACARS CPDLC via (another) 3rd party client during the enroute phase of US operations?  I was asked by a few separate pilots if I was CPDLC capable and utilizing that service.  I have found the client that was referred to for review.  I don't know if it is acceptable (or restricted) since it is not listed in Vatsim's policies for approved clients. 

I am not promoting for them, just inquiring with the brain-trust on here.  This is the link to their homepage.

 http://www.hoppie.nl/acars/prg/atc/