There was a discussion on an earlier thread (https://news.ycombinator.com/item?id=7489401) about bringing App Stores to servers. Would people use and/or pay for something like this?
Untangle is a firewall with its own app store, and it works great! It's hard to imagine a firewall app store, but once you start using it, it just makes sense.
[1]: https://bitnami.com/