This app has been deleted or is hidden to the public. There is extremely limited to no information about this app.
We don't even have a name, hence why we are displaying SteamDB Unknown App "AppID".
If you see someone screenshot a page like this and add some information/images on it, it is most likely fake.
Every change is tracked in history, and can be directly linked to.
<iframe src="https://steamdb.info/embed/?appid=399720" height="389px" width="100%" scrolling="no" frameborder="0"></iframe>
Initializing graph of a week…
Initializing graph of a year…
|SubID||Name||Billing Type||Last Updated|
|77540||XO Developer Comp||CD Key||November 4, 2015 – 01:23:52 UTC|
|77541||XO for Beta Testing||CD Key||November 4, 2015 – 01:23:52 UTC|
|77542||XO||Store or CD Key||November 4, 2015 – 01:23:52 UTC|