So most probably, the app is now abandoned for lack of financial support?
I do not think so, it has already happened in 2016.
Anyone else notice that preev.com is down?
Heroku | No such app
There is no app configured at that hostname.
Perhaps the app owner has renamed it, or you mistyped the URL.
A day later, the same user reported that the site had returned.
Hell, who is developing that site, and how does it gain from developing that interface?
I read some comments and found no answer. Unknown site and unknown developer.