I have been using Verifyle for 2 or 3 years (was free through the State CPA Society as a benefit but that is over) so I paid for it this year. I like it, and I never would have predicted 5  years ago that I would be sending a decent amount of my clients their returns through a cloud portal. Verifyle also has electronic signing built in, so I get my 8879's signed that way when I send that along with the return to the client. 

It probably wouldnt work for everyone, but it works for me.