Android application firewall - interactive prompt confirmation for connections I'm thinking of developing application, or probably extending AFWall+ app

What I'm missing on Android is possibility to confirm each connection from each application, simply blocking the application on some networks is already solved, but I want to have very specific control over what URLs/IPs the application is talking to.

I've made proposal https://github.com/ukanth/afwall/issues/269
Which is generally the same functionality as provided on OS X from Little Snitch application firewall. Possibility to create time-domain-port rules per application (unix uid/guid)

I'm thinking about using some kind of mashup of IPTables and possibly intercepting sock_create syscall. It will be open-source and free, if anybody wants to jump on the bandwagon, you're welcome. 

So the question is, is there anything like this already done? Even paid applications.
I haven't really found anything like that, so I'd just like to be sure, before jumping into development of such large thing :-)
I'd certainly like to see something like this, the best I could find so far was XPrivacy (root required) which you can setup to restrict Internet connections. However unless you apply a global template (license purchase required for batch apply) this is per app. Though maybe you can manipulate the system Internet process, I haven't investigated upon that so far (it's an expert setting with a very RED background, I don't want to mess up my system too much...). Though I'd certainly love to restrict tethering such that a connected Windows Laptop won't waste my data quota for updates...