Im pretty sure jusgray is the site owner of appzmarket. So as this question is directed at "Has anyone sold any assets on appzmarket.com ?" then the answer is probably not !
Yeah the feedback and reviews given on the site may look real, but it sure looks like the site owner has actually created several accounts and is able to leave feedback to make it look like buyers have actually placed an order. I have spoken to several members of the site who have all said the same thing. "that there main source of income is fiverr"
And if you are suspended or blocked from the site, the "owner" or "admin" does not remove your job listings, but takes them on himself offering potential buyers your jobs. So please do not be surprised if you receive a message from appzmarket telling you that they cannot fulfill your order.
I have not seen any promotions for the site owners other than video`s on youtube and there facebook page was last updated February 24 (now April 18) which also leads you believe that this was just a passing thought to try and earn some cash on auto pilot. Serious minded people would be promoting services available to buyers, like fiverr sellers are constantly doing to find new customers.
At the end of the day it is simply a website unknown to millions who scour the internet daily looking for these types of services and end up going elsewhere. As we all know, a couple of hundred backlinks on forums such as this and a few videos on youtube is not going to make the owners of appzmarket millionaires any time soon.
UPDATE: On my findings i have also come across the website "appzmarket" to be giving away some of 
Kenny free assets simply to gain positive feedback as sellers.. Im quite sure this may be a copyright infringment !!