Do you like round icons? Than Quantum Dots is the right icon pack for you!
The app has over 400 HD icons and also many handcrafted wallpapers. And if this isn't enough, there are even some Zooper widgets for you.
The design of the icons is based on Material Design combined with some kind of uniformity, what I think is a really good mix. The icons just look very professional. According to the description on Google Play, every icon is handcrafted.
The app supports almost every custom launcher, because it's based on the icon pack dashboard IconShowcase. So there's no problem, to use it with Nova Launcher, Action Launcher, Apexâ€¦
If you want to get involved into the development of the icon pack, there's a community on Google+, where you can submit feedback and suggestions.
Unfortunately the app isn't for free, but it's definitely worth to buy the app.