For a while, I was using Calyx, and the default install includes an fdroid that did something like this, but it seemed to find anti-features in pretty much every app. I didn't find it terribly useful. 

i don't install many apps, so if I'm installing something it's because I'm pretty sure I need it. I really only want to know if there's a major problem.

Scoresby

Its a problem, yes. So how do we fix it?  There's the F-droid model where things get flagged up that are "anti-features", but I wonder how many people actually read it?